Updated docker build process for bank app

[anandhakumarpalanisamy]

updated docker build process with respect to https://github.com/bityoga/articonf-bank-app/pull/3

• changed docker image build process to utilise scritp in bank upp repository.
• removed unused bankapp docker template
• modified bank playbook to use ansible's "docker_swarm_service" instead of native docker service create.