Update build.gradle

- Update to Shadow 1.0.1
- Update to license-gradle-plugin 0.9.0
- Update to coveralls-gradle-plugin 0.5.0
- Re-add repositories for buildscripts (this was needed for the project
  repos, this is simply done to avoid confusion)
- Include magma.gradle script to allow offline compilation and not depend on the status of obsidianbox.org

Signed-off-by: Steven Downer <grinch@outlook.com>