prepare for minor bug fix release (#181)

* prepare for minor bug fix release

* fix hurried changelog entry

Author: thomaszurkan-optimizely

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Optimizely Java X SDK Changelog
 
+## 2.0.1
+
+April 25th, 2018
+
+This is a patch release of the Optimizely SDK for 2.0.0 which is a major release.
+
+### Bug Fixes
+* Checking for invalid variables passed into getEnabledFeature, Activate, getVariation and track.
+
 ## 2.0.0
 
 April 12th, 2018