Add android.permission.READ_EXTERNAL_STORAGE

On my Nexus 5 running 4.4 the app crashes whenever I change songs. The message says it is missing this permission. It works perfectly after I add it locally.
Update README.md

Added working report for Google Nexus 4.
Merge pull request #108 from the-lay/patch-1

Update README.md
Merge pull request #107 from klusark/patch-1

Add android.permission.READ_EXTERNAL_STORAGE