Move Gemfile development dependencies to gemspec and remove unused development dependencies

- Removes coolline
- Removes redcarpet
Add coolline back as a dependency
Speed up Apply feature
Speed up Config feature
Merge pull request #552 from sethvargo/faster_apply

Speed up Apply feature
Merge pull request #553 from sethvargo/faster_config

Speed up Config feature
Merge pull request #551 from sethvargo/move_gemfile

Move Gemfile development dependencies to gemspec
Speed up Configure feature
Speed up Contingent feature
Speed up Cookbook feature
Speed up Groups feature
Merge pull request #554 from sethvargo/faster_configure

Speed up Configure feature
Speed up List feature
Merge pull request #555 from sethvargo/faster_contingent

Speed up Contingent feature
Speed up Lockfile feature
Merge pull request #556 from sethvargo/faster_cookbook

Speed up Cookbook feature
Speed up Open feature
Speed up Outdated command
Merge pull request #557 from sethvargo/faster_groups

Speed up Groups feature
Speed up Package feature