Cleanup of imports

[brianredbeard]

At some point (just for readability) package imports should get cleaned up. An example of doing this well is at
https://github.com/coreos/mayday/blob/master/mayday.go

In that case, there are three basic groups of packages:

• standard libraries
• 'local' libraries
• third party libraries

go fmt correctly handles this behavior and will sort them correctly in each area.

One example of where cleanup should occur is this:

https://github.com/coreos/mayday/blob/master/mayday/plugins/docker/docker.go

Extremely low priority. Mainly just here for tracking purposes.