fixed errata 'com.robolectric' -> 'org.robolectric'
Update README.md

fix typo
Add section on compatibility
Merge pull request #1 from behumble/patch-1

fixed errata 'com.robolectric' -> 'org.robolectric'
Merge pull request #2 from skyisle/patch-1

Update README.md
Merge branch 'upstreamMaster'