update build tools version to 20.0.0
properly initialize in CircleImageView(Context) constructor
Merge pull request #15 from mutahirqureshi/non-xml-init

properly initialize in CircleImageView(Context) constructor
Merge pull request #16 from mutahirqureshi/build-tools

update build tools version to 20.0.0
Add support for setImageURI
Prepare release v1.2.0
Prepare for next release