Do not require user to run /entrypoint when exec'ing into container

[sirn]

Right now we set environment variables in /entrypoint. This means any invocation of docker exec (or the equivalent) will require prefixing the command with /entrypoint, e.g. docker exec -it ewallet /entrypoint /bin/ewallet remote_console

Steps to reproduce

See above

Expected behavior

I should be able to run docker exec -it ewallet /bin/ewallet remote_console without doing the /entrypoint

Actual behavior

I need /entrypoint