Move gps package out of internal

[tamalsaha]

gomvpkg -from github.com/golang/dep/internal/gps -to github.com/golang/dep/gps

Fixes #575

[sdboyer]

(I requested this 😁)

let's see how tests so. also, @tamalsaha , I think we have an issue open for this - do you mind searching the queue for it?

/cc @spenczar - I know you were looking forward to this 😀

[tamalsaha]

Added issue #. I am not sure what's wrong with codeclimate. Other tests are passing.

[tamalsaha]

updated CHANGELOG

[tamalsaha]

Are these tests known to be flaky? They started failing after I updated the CHANGELOG file.

[sdboyer]

the appveyor tests can be, yes. that particular failure is on a new test recently introduced for adaptive healing of the cache area. we've seen a couple other instances of flakiness from that.

the travis failure was on tip, so i'm gambling on a regression there. i've restarted both.

[sdboyer]

oh, the codeclimate failure is likely because we have some CI which knows dirs to exclude that needs to be updated.

it's worth grepping over the repo for instances of internal/gps in general (whether in *.go files or not) and seeing what may need fixing.

[tamalsaha]

All tests are now passing except go:tip .

[sdboyer]

big shift here, but i think we're looking good!