Merge pull request #1591 from MetaMask/ignore-package-lock

gitignore - add package-lock and re-arrange by category

.gitignore

@@ -1,21 +1,27 @@
-dist
 npm-debug.log
 node_modules
-temp
-.tmp
-.sass-cache
+package-lock.json
+
 app/bower_components
 test/bower_components
 package
+
+temp
+.tmp
+.sass-cache
 .DS_Store
+app/.DS_Store
+
+dist
 builds/
 disc/
-notes.txt
-app/.DS_Store
-development/bundle.js
 builds.zip
-test/integration/bundle.js
+
+development/bundle.js
 development/states.js
+test/integration/bundle.js
 test/background.js
 test/bundle.js
 test/test-bundle.js
+
+notes.txt