v1.4.0

Changes

• Added enter command. To enter a container, simply run enter <container name> (e.g. enter api or enter api /bin/sh).
• Automatically detect and load .env, .env.local, .env.docker and .env.docker.local files when running docker commands (using the --env-file parameter).

Note: due to little time, tests are probably failing but me and my colleagues use this all day, every day so this has been battle tested. If there are any bugs, they'll be fixed quickly. Once I find the time (hopefully soon), I'll update the tests as well.