Update build.gradle

- Update Shadow to 1.0.2 (officially supports Gradle 2.0)
- Fix dependency groupId for Magma

Signed-off-by: Steven Downer <grinch@outlook.com>
Update for Magma changes

Signed-off-by: Steven Downer <grinch@outlook.com>
Update gradle-wrapper.properties to use Gradle 2.0

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