v1.4.0 better support when running in docker env

- support reading configs from environment variable.
  all config key can be configured by env variable.
  This feature is introduced in wells 1.4.0.
- add another configuration file position /etc/{{name}}/{{name}}.conf
  to allow easier volume mount in kubernetes.
- ci-build docker run use go user
- add host and port in app default configuration
- replace pep8 by pycodestyle