Update changelog.

Author: yfakariya

CHANGES.txt

@@ -619,7 +619,7 @@ Release 0.9.0 beta1 2016/09/24
   BUG FIXES
   * Fix nuspec to prevent old NuGet clients which do not support .NET Standard TFMs. Issue #177.
 
-Release 0.9.0 beta2 2017/2/11
+Release 0.9.0 beta2 2017/2/12
 
   NEW FEATURES
   * Users of serializer code generator API can specify TextWriter to output. This may improve tooling chain.