Updated buid files.
Updated build files: added test targets.
Prefixed Integration Tests with "IT".
Added junit and jacoco libraries. 
Updated build files with coverage tests.
Changed test target to project-test.
Merged both decryption methods.
Merged decrypt base64 string method with default decrypt method. 
Added @Test annotation to GifDecoder tester.
Call project-clean first, before calling project-test.