add: Cleanup and bug fix

* Remove ability to add a second dep since that never worked anyway
* Remove promptBool (newly unused)
* Update Documentation
General cleanup

* Fix golint problems
* Expand makefile to run depman with various flags
* Makefile should test using golint
Bump Copyright year
Run goimports
Reorganize documentation to support Github and Godoc.org

* Move Readme content into doc.go
* Edit and cleanup documentation
* 'make doc' will now generate Readme.md from doc.go
* Add godocdown as dependency
* Update dependencies to latest versions
Merge branch 'master' into feature-cleanup

* master:
  upgrade: Fixes and cleanups from pull request
  Add documentation for upgrade checks
  Implement async upgrade checker

Conflicts:
	Readme.md
upgrade: fix golint warning
Bump version to 2.9.1
Merge pull request #27 from vube/feature-cleanup

Feature cleanup