Added prettier with staged commit hook - #1205

Author: Aaron Tobias

.prettierignore

@@ -0,0 +1,9 @@
+dist/
+test/
+assets/
+
+app/**/*.react.js
+app/addons/.module-cache
+app/addons/**/assets/*
+app/addons/**/dependencies/*
+app/load_addons.js

.prettierrc

@@ -0,0 +1,7 @@
+{
+  "trailingComma": "es5",
+  "semi": true,
+  "singleQuote": true,
+  "bracketSpacing": false,
+  "printWidth": 120
+}