[CR] [000] remove unnecessary dependencies
 - Remove Slim
 - Remove OJ
 - Remove Rabl
 - Switch to ERB for templating
 - Only specify minimum version for dependencies
Merge branch 'dev' into cr_switch_to_erb

Conflicts:
	lib/ops/version.rb
	ops.gemspec
Merge pull request #4 from primedia/cr_switch_to_erb

[CR] [000] remove unnecessary dependencies