Tidy up package.json (#87)

* Be more explicit about which files we export

* Update changelog

Author: atrakh

CHANGELOG.md

@@ -10,6 +10,9 @@ This project adheres to [Semantic Versioning](http://semver.org).
 ### Deprecated:
 - Default exports, use named exports instead.
 
+### Changed:
+- Updated `package.json` to only export minified files.
+
 ## [2.3.1] - 2018-06-29
 ### Fixed:
 - If a polling request has failed due to an invalid environment key, calling `variation` now returns the default value; previously, it sometimes caused a null reference error.

package.json

@@ -10,8 +10,12 @@
     "client"
   ],
   "files": [
-    "src",
-    "dist"
+    "ldclient.cjs.js",
+    "ldclient.cjs.js.map",
+    "ldclient.es.js",
+    "ldclient.es.js.map",
+    "ldclient.min.js",
+    "ldclient.min.js.map"
   ],
   "main": "dist/ldclient.cjs.js",
   "module": "dist/ldclient.es.js",