Merge branch 'master' of github.com:ripple/gatewayd
[TASK] Extract capistrano to gatewayd/gatewayd-capistrano.
[TASK] Extract Docker functionaly to gatewayd/gatewayd-docker.
[FIX] set to a certain amount instead of always 0
[FIX] pass cold wallet address only to callback
[FEATURE] accept amount
[TASK] accept 0 if amount is not provided
[TASK] bump ripple-rest-client version
[DOC] Fix typo and add information about superuser role in postgres