Update README with GA verbiage (#247)

* Update README with GA verbiage

* Update README.md

Co-Authored-By: David Supplee <dwsupplee@gmail.com>

Author: jdpedrie

README.md

@@ -41,9 +41,7 @@ Versioning
 
 This library follows [Semantic Versioning][].
 
-It is currently in major version zero (``0.y.z``), which means that anything
-may change at any time and the public API should not be considered
-stable.
+This library is considered GA (generally available). As such, it will not introduce backwards-incompatible changes in any minor or patch releases. We will address issues and requests with the highest priority.
 
 [Semantic Versioning]: http://semver.org/