Make es5.js the main file of the package

fixes #239

README.md

@@ -26,15 +26,14 @@ First of all, require the library:
 const bowser = require('bowser');
 ```
 
-By default, `require('bowser')` requires the *ES6 version of files*, which
+By default, `require('bowser')` requires the *ES5 version of files*, which
 **do not** include any polyfills.
 
 In case if you don't use your own `babel-polyfill` you may need to have pre-built bundle with all needed polyfills.
 So, for you it's suitable to require bowser like this: `require('bowser/bundled')`.
 As the result, you get a ES5 version of bowser with `babel-polyfill` bundled together.
 
-If you use bowser for Node.js, you'd better use `require('bowser/es5')`,
+You may need to use the source files, so they will be available in the package as well.
-since source files have `import` statements, which are not compatible with Node.js yet.
 
 ## Browser props detection
 

package.json

@@ -20,7 +20,7 @@
       "url": "http://twitter.com/lancedikson"
     }
   ],
-  "main": "src/bowser.js",
+  "main": "es5.js",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/lancedikson/bowser.git"