Merge pull request #5 from edubarr/feature/appcompat

Feature/appcompat
Using styles for compatibility.
Upgrading retrolambda to version 2.4.0
Merge remote-tracking branch 'origin/dev' into dev
Fix bug where realm crashed due to access from different threads.
Merge branch 'dev' into feature/appcompat
Change app styles and colours.
Fix bug where toast referenced a null context.
Merge branch 'dev' into feature/appcompat
Removing unnecessary uses-sdk tag from manifest.
Adjust cardview style.