Fix how secondView layout is updated when onLayout method is invoked.
Update version name to 1.3 and version code to 8.
Update README.md with info related to version 1.3
Update version name and version code to next release number.
Add check style configuration
Apply new check style to draggablepanel module
Apply new check style to sample module
Fix more check style problems.
Add checkstyle task to CI
Fix .travis.yml configuration
Update max line length from 100 to 120