chore(gitignore): Add c9 to gitignore

mikeumus · filipesilva · commit 71423a136744 · 2016-10-28T17:44:26.000+01:00
Adding `.c9` to `.gitignore`. `.c9` is from Cloud9 IDE, an editor in the browser. Partnered with Google to [connect Google App Engine apps](https://c9.io/blog/build-apps-for-google-cloud-platform-on-cloud9/). [Purchased by Amazon](https://c9.io/blog/great-news/) a month ago. The best way to code on a Chromebook. Close angular#2782
diff --git a/packages/angular-cli/blueprints/ng2/files/gitignore b/packages/angular-cli/blueprints/ng2/files/gitignore
@@ -13,6 +13,7 @@
 /.vscode
 .project
 .classpath
+.c9/
 *.launch
 .settings/
 
