Drop golang 1.7 builds

Merge pull request 99designs#141 from 99designs/refactor-order-in-whi…

…ch-access-to-keychain-is-requested

Refactor order in which access to keychain is requested

Merge pull request 99designs#117 from 99designs/update-jose2go

Update jose2go dep

Provide an admin policy for federated login

Merge pull request 99designs#107 from hraban/exitcode

exec: Exit with exit code of subcommand

Update readme

Update codesign to use updated cert

Merge pull request 99designs#75 from 99designs/optional-stdout

Stdout parameter to not open login URL in default browser

Add missing vendored libs to fix 99designs#69

Merge pull request 99designs#63 from 99designs/file-backend

Add a basic file backend