Added code coverage (JaCoCo and Coveralls) to Maven pom.
- also added Code style (Checkstyle), static analysis (PMD), and project info reports.
- now use Surefire to run the unit tests.
- also updated slf4j to version 1.7.7 and Maven Checkstyle plugin to 2.12.1.
Merge pull request #13 from FreekDB/master

Added code coverage (JaCoCo and Coveralls) to Maven pom.