By allowing partial matches of selectors there are chances of collisions
such as those in issue #145, this removes it to expect explicit packages
for each rule.
Closes#145
- Get rid of 'core' and move CLI to cmd/gas directory
- Migrate (most) tests to use Ginkgo and testutils framework
- GAS now expects package to reside in $GOPATH
- GAS now can resolve dependencies for better type checking (if package
on GOPATH)
- Simplified public API