chore(package.json): upgrade grunt-contrib-compress to v0.12.0
chore(package.json): upgrade grunt-contrib-copy to v0.6.0
chore(package.json): upgrade grunt-contrib-uglify to v0.6.0
chore(package.json): upgrade grunt-karma to v0.9.0
chore(package.json): upgrade grunt-shell to v1.1.1
chore(package.json): upgrade semver to v4.0.0

Closes #55