fix(lint): Remove deprecated eslint rule

see airbnb/javascript#978

Author: avalleteau

.eslintrc

@@ -251,7 +251,6 @@
     "react/prefer-es6-class": 1, //Use ES6 Class instead of Reacy.createClass
     "react/prop-types": 1, //Prevent missing props validation in a React component definition
     "react/react-in-jsx-scope": 1, //Prevent missing React when using JSX
-    "react/require-extension": 1, //Restrict file extensions that may be required
     "react/self-closing-comp": 1, //Prevent extra closing tags for components without children
     "react/sort-comp": 1, //Enforce component methods order
     "react/wrap-multilines": 0 //Prevent missing parentheses around multiline JSX