add gem ignores

Author: codebender

.gitignore

@@ -27,9 +27,10 @@ build/
 
 # for a library or gem, you might want to ignore these files since the code is
 # intended to run in multiple environments; otherwise, check them in:
-# Gemfile.lock
-# .ruby-version
-# .ruby-gemset
+Gemfile.lock
+.ruby-version
+.ruby-gemset
+.rspec
 
 # unless supporting rvm < 1.11.0 or doing something fancy, ignore this:
 .rvmrc