use regex for stripping quotes

Author: jseminck

lib/rules/no-unused-prop-types.js

@@ -263,10 +263,7 @@ module.exports = {
      * @param {string} the identifier to strip
      */
     function stripQuotes(string) {
-      if (string[0] === '\'' || string[0] === '"' && string[0] === string[string.length - 1]) {
-        return string.slice(1, string.length - 1);
-      }
-      return string;
+      return string.replace(/^\'|\'$/g, '');
     }
 
     /**

lib/rules/prop-types.js

@@ -333,10 +333,7 @@ module.exports = {
      * @param {string} the identifier to strip
      */
     function stripQuotes(string) {
-      if (string[0] === '\'' || string[0] === '"' && string[0] === string[string.length - 1]) {
-        return string.slice(1, string.length - 1);
-      }
-      return string;
+      return string.replace(/^\'|\'$/g, '');
     }
 
     /**