[BUG] Require setKey in getKey api call.
[TEST] write basic status code tests for HTTP controllers
[CHORE] refactor to take callback
[CHORE] refactor to take callback param
[CHORE] refactor startGateway function to take callback.
[FEATURE] generate wallet via the http controller.
[CHORE] update http call to set hot wallet on callback
[CHORE] fire callback with error or processes
[BUG] update method name to startGateway
[CHORE] pass callback on process start
[TEST] write basic status code tests for HTTP controllers
[BUG] require gateway
[BUG] try catch gateway start

Revert "[CHORE] pass callback on process start"

This reverts commit 9be9e829cf721b24a348f65b1541772d78175d23.

Revert "[CHORE] fire callback with error or processes"

This reverts commit 9a5fc4935bb6e755c4a242259bc416fa4acdad37.

Revert "[CHORE] refactor startGateway function to take callback."

This reverts commit 6cf2e71a48801b7b6edee80d28806a48bc83aa17.
[BUG] require config instead of gateway
[CHORE] extra line clean up
Merge branch 'http-api-tests' of github.com:ripple/gatewayd into http-api-tests