diff --git a/.travis.yml b/.travis.yml
index 27000a962..30972bfb5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,34 +1,32 @@
+sudo: required
+dist: trusty
 language: php
-
 php:
-  - 7
-  - 7.1
-
-matrix:
-  fast_finish: true
-
-sudo: false
+  - "7.2"
+  - "7.1"
 
 services:
-  - mongodb
-  - mysql
-
-addons:
-  apt:
-    sources:
-    - mongodb-3.0-precise
-    packages:
-    - mongodb-org-server
-
-before_script:
-  - pecl install mongodb
-  - mysql -e 'create database unittest;'
-  - travis_retry composer self-update
-  - travis_retry composer install --no-interaction
+  - docker
+
+install:
+  # Update docker-engine using Ubuntu 'trusty' apt repo
+  - >
+    curl -sSL "https://get.docker.com/gpg" |
+     sudo -E apt-key add -
+  - >
+    echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" |
+     sudo tee -a /etc/apt/sources.list
+  - sudo apt-get update
+  - >
+    sudo apt-get -o Dpkg::Options::="--force-confdef" \
+     -o Dpkg::Options::="--force-confold" --assume-yes install docker-engine --allow-unauthenticated
+  - docker version
+
+  # Update docker-compose via pip
+  - sudo pip install docker-compose
+  - docker-compose version
+  - docker-compose up --build -d
+  - docker ps -a
 
 script:
-  - mkdir -p build/logs
-  - vendor/bin/phpunit --coverage-clover build/logs/clover.xml
-
-after_success:
-  - sh -c 'php vendor/bin/coveralls -v'
+  - docker-compose up --exit-code-from php
diff --git a/composer.json b/composer.json
index 8655bd45c..ce32f6407 100644
--- a/composer.json
+++ b/composer.json
@@ -11,14 +11,14 @@
     ],
     "license" : "MIT",
     "require": {
-        "illuminate/support": "^5.5",
-        "illuminate/container": "^5.5",
-        "illuminate/database": "^5.5",
-        "illuminate/events": "^5.5",
+        "illuminate/support": "^5.6",
+        "illuminate/container": "^5.6",
+        "illuminate/database": "^5.6",
+        "illuminate/events": "^5.6",
         "mongodb/mongodb": "^1.0.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.0",
+        "phpunit/phpunit": "^6.0|^7.0",
         "orchestra/testbench": "^3.1",
         "mockery/mockery": "^1.0",
         "satooshi/php-coveralls": "^2.0",
diff --git a/docker-compose.yml b/docker-compose.yml
index 6c2c773bb..ce5c95652 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,6 +3,7 @@ version: '3'
 services:
 
     php:
+        container_name: php
         build:
             context: .
             dockerfile: docker/Dockerfile
@@ -15,6 +16,7 @@ services:
           - mongodb
 
     mysql:
+        container_name: mysql
         image: mysql
         environment:
             MYSQL_ROOT_PASSWORD:
@@ -24,6 +26,7 @@ services:
             driver: none
 
     mongodb:
+        container_name: mongodb
         image: mongo
         logging:
             driver: none
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 0ba057324..62c68e45d 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,6 +1,14 @@
 FROM php:7.1-cli
 
+RUN pecl install xdebug
+
 RUN apt-get update && \
-    apt-get install -y autoconf pkg-config libssl-dev && \
-    pecl install mongodb && docker-php-ext-enable mongodb && \
-    docker-php-ext-install -j$(nproc) pdo pdo_mysql
+    apt-get install -y autoconf pkg-config libssl-dev git && \
+    pecl install mongodb git zlib1g-dev && docker-php-ext-enable mongodb && \
+    docker-php-ext-install -j$(nproc) pdo pdo_mysql zip && docker-php-ext-enable xdebug
+
+RUN curl -sS https://getcomposer.org/installer | php \
+    && mv composer.phar /usr/local/bin/ \
+    && ln -s /usr/local/bin/composer.phar /usr/local/bin/composer
+
+ENV PATH="~/.composer/vendor/bin:./vendor/bin:${PATH}"
\ No newline at end of file
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index ecff3cf08..c646f3917 100755
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-sleep 3 && php ./vendor/bin/phpunit
+sleep 3 && composer install --prefer-source --no-interaction && php ./vendor/bin/phpunit
diff --git a/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php b/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
index 7f9b511ae..34b8b5788 100644
--- a/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
+++ b/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
@@ -169,9 +169,10 @@ public function belongsTo($related, $foreignKey = null, $otherKey = null, $relat
      * @param  string $name
      * @param  string $type
      * @param  string $id
+     * @param  string $ownerKey
      * @return \Illuminate\Database\Eloquent\Relations\MorphTo
      */
-    public function morphTo($name = null, $type = null, $id = null)
+    public function morphTo($name = null, $type = null, $id = null, $ownerKey = null)
     {
         // If no name is provided, we will use the backtrace to get the function name
         // since that is most likely the name of the polymorphic interface. We can
diff --git a/src/Jenssegers/Mongodb/Eloquent/Model.php b/src/Jenssegers/Mongodb/Eloquent/Model.php
index 38b3858f8..86f8ef3b5 100644
--- a/src/Jenssegers/Mongodb/Eloquent/Model.php
+++ b/src/Jenssegers/Mongodb/Eloquent/Model.php
@@ -101,7 +101,7 @@ protected function asDateTime($value)
     /**
      * @inheritdoc
      */
-    protected function getDateFormat()
+    public function getDateFormat()
     {
         return $this->dateFormat ?: 'Y-m-d H:i:s';
     }
diff --git a/src/Jenssegers/Mongodb/Queue/MongoQueue.php b/src/Jenssegers/Mongodb/Queue/MongoQueue.php
index ed7e9c2ed..e9cd8da9c 100644
--- a/src/Jenssegers/Mongodb/Queue/MongoQueue.php
+++ b/src/Jenssegers/Mongodb/Queue/MongoQueue.php
@@ -117,7 +117,7 @@ protected function releaseJobsThatHaveBeenReservedTooLong($queue)
             })->get();
 
         foreach ($reserved as $job) {
-            $attempts = $job['attempts'];
+            $attempts = $job['attempts'] + 1;
             $this->releaseJob($job['_id'], $attempts);
         }
     }
diff --git a/src/Jenssegers/Mongodb/Schema/Builder.php b/src/Jenssegers/Mongodb/Schema/Builder.php
index e30e162b7..799fe8e80 100644
--- a/src/Jenssegers/Mongodb/Schema/Builder.php
+++ b/src/Jenssegers/Mongodb/Schema/Builder.php
@@ -96,6 +96,18 @@ public function create($collection, Closure $callback = null)
         }
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function dropIfExists($collection)
+    {
+        if ($this->hasCollection($collection)) {
+            return $this->drop($collection);
+        }
+
+        return false;
+    }
+
     /**
      * @inheritdoc
      */
diff --git a/tests/models/User.php b/tests/models/User.php
index ded0a3966..d233c3f32 100644
--- a/tests/models/User.php
+++ b/tests/models/User.php
@@ -65,7 +65,7 @@ public function father()
         return $this->embedsOne('User');
     }
 
-    protected function getDateFormat()
+    public function getDateFormat()
     {
         return 'l jS \of F Y h:i:s A';
     }