Update README.md with Java 7 support (#577)

Author: chingor13

README.md

@@ -13,7 +13,7 @@ content. The JSON and XML libraries are also fully pluggable, and they include s
 
 The library supports the following Java environments:
 
-- Java 6 (or higher)
+- Java 7 (or higher)
 - Android 4.0 (Ice Cream Sandwich) (or higher)
 - GoogleAppEngine Google App Engine
 
@@ -47,16 +47,3 @@ Java 11 | [![Kokoro CI](https://storage.googleapis.com/cloud-devrel-public/java/
 ## Links
 
 - [Discuss](https://groups.google.com/group/google-http-java-client)
-
-## Notice: Ending Java 6 Support
-
-Please note: since Java 6 extended support is being ended this December by Oracle, we will begin
-ending Java 6 support in early 2019, with release 1.28.0 as a tentative goal. Users may stay still
-use these libraries in Java 6 projects for some time, but going forward we will not ensure that
-these libraries work in such an environment. After 1.28.0, our supported versions will include Java
-7 and onward.
-
-For Android users, we will continue our 4.0 support.
-
-For questions or concerns, please file an issue in the GitHub repository.
-