sort-comp instantiates regex from eslintrc properly (facebook#69)

* sort-comp instantiates regex from eslintrc properly

This fixes the issue where react/sort-comp eslint rules such as `"/^render+.$/"` are incorrectly converted to `/\/^render.+$\//` rather than `/^render.+$/`

* convert actual regex to strings (like how it is in .eslintrc)

transforms/sort-comp.js

@@ -122,10 +122,10 @@ const defaultMethodsOrder = [
   'componentWillUpdate',
   'componentDidUpdate',
   'componentWillUnmount',
-  /^on.+$/,
-  /^(get|set)(?!(InitialState$|DefaultProps$|ChildContext$)).+$/,
+  '/^on.+$/',
+  '/^(get|set)(?!(InitialState$|DefaultProps$|ChildContext$)).+$/',
   'everything-else',
-  /^render.+$/,
+  '/^render.+$/',
   'render',
 ];
 
@@ -146,7 +146,8 @@ function selectorMatches(selector, method) {
   const selectorIsRe = regExpRegExp.test(selector);
 
   if (selectorIsRe) {
-    const selectorRe = new RegExp(selector);
+    const match = selector.match(regExpRegExp);
+    const selectorRe = new RegExp(match[1], match[2]);
     return selectorRe.test(methodName);
   }