adds more ignore files and force to clean lib before compiling

.npmignore

@@ -1,4 +1,6 @@
+.*
+coverage/
 demo/
 webpack.config.js
-__tests__/
+src/**/__tests__
 karma.conf.js

package.json

@@ -78,7 +78,7 @@
     "test": "karma start --single-run",
     "posttest": "npm run lint",
     "lint": "eslint .",
-    "compile": "babel src --ignore __tests__ --out-dir lib",
+    "compile": "rm -rf lib && babel src --ignore __tests__ --out-dir lib",
     "prepublish": "npm run compile",
     "demo": "webpack-dev-server --content-base ."
   }