Add no trailing whitespace and force eol at end of file. (#3154)

.eslintrc.json

@@ -15,6 +15,8 @@
     },
     "rules": {
         "indent": ["error", 2],
-        "linebreak-style": ["error", "unix"]
+        "linebreak-style": ["error", "unix"],
+        "no-trailing-spaces": 2,
+        "eol-last": 2
     }
 }