Update .gitignore

Author: Nicolas Rodriguez

.gitignore

@@ -1,18 +1,16 @@
-*.gem
-*.rbc
-.bundle
-.config
-.yardoc
-Gemfile.lock
-InstalledFiles
-_yardoc
-coverage
-doc/
-lib/bundler/man
-pkg
-rdoc
-spec/reports
-test/tmp
-test/version_tmp
-tmp
-gemfiles/*.lock
+# Ignore bundler config.
+/.bundle
+
+# Ignore Gemfile.lock
+/Gemfile.lock
+/gemfiles/*.lock
+
+# Ignore test files
+/coverage
+/tmp
+
+# RVM files
+/.ruby-version
+
+# Gem files
+/*.gem