test(integration): add basic working framework files
test(integration): working versions of auth and keys commands
chore(tests/integration): vendor json library and adjust indentation
test(integration): working integration tests

Also vendored in the gexpect library for tests.
test(integration): add regression tests for two issues

See github issues #1136 and #1239.

Removed example-play as its taking too much time.
Added `curl` test for each test that launches an app.
refactor(tests/integration): move to common tests package
Merge pull request #1379 from deis/integration-tests

feat(tests): add integration tests