Remove magma_ prefix from gradle script

Signed-off-by: Steven Downer <grinch@outlook.com>
Re-add project repositories

- Removed install task from default tasks

Signed-off-by: Steven Downer <grinch@outlook.com>
Revert to Shadow 0.8

- Shadow 1.0.1 doesn't pull in the obfuscated classes which results in an
  unobfuscated mod.

Signed-off-by: Steven Downer <grinch@outlook.com>
Use distributions jar during reobf task, will include Magma during
obfuscation

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