chore: remove outdated announcements

Author: Sam Harrison

README.md

@@ -22,7 +22,6 @@ If you are looking for the SendGrid API client library, please see [this repo](h
 
 <a name="announcements"></a>
 # Announcements
-**The default branch name for this repository has been changed to `main` as of 07/27/2020.**
 
 All updates to this project are documented in our [CHANGELOG](CHANGELOG.md).
 
@@ -60,10 +59,6 @@ repositories {
 
 `mvn install`
 
-## Install via Fat Jar
-
-[sendgrid-java-latest.jar](http://dx.sendgrid.com/downloads/java-http-client/java-http-client-latest.jar)
-
 ## Dependencies
 
 - Please see the [pom.xml file](pom.xml)