Add rule no-case-declarations

Author: Justin Kalland

eslintrc.json

@@ -68,6 +68,7 @@
     "new-parens": "error",
     "no-array-constructor": "error",
     "no-caller": "error",
+    "no-case-declarations": "error",
     "no-class-assign": "error",
     "no-compare-neg-zero": "error",
     "no-cond-assign": "error",