Disable no-undefined

This disables the no-undefined rule. Most JavaScript projects in
OpenStack, at this point, have adopted eslint-config-angular, which
declares the 'definedundefined' rule requiring angular.isDefined()
or angular.isUndefined() to handle this case. That makes this
rule redundant, while also forcing non-production pieces of code
(such as unit tests) to become unnecessarily verbose.

https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/definedundefined.md
http://eslint.org/docs/rules/no-undefined

Change-Id: I35ae5c8bc9e7ebb5c455d4acbe79636653448f65

.eslintrc

@@ -461,7 +461,7 @@ rules:
 
   # Disallow use of undefined variable
   # http://eslint.org/docs/rules/no-undefined
-  no-undefined: 2
+  no-undefined: 0
 
   # Disallow declaration of variables that are not used in the code
   # http://eslint.org/docs/rules/no-unused-vars