App commands should all accept `-e` option to set HANAMI_ENV

[timriley]

[jodosha]

@timriley I'm torn.

Wouldn't this complicate the understanding and implementation of CLI? If we introduce -e it will create a matrix of possibilities: CLI argument vs ENV var.

ENV	CLI	Result
not set	not set	Apply default: development, unless running tests (default is test)
set	not set	Apply given ENV var
not set	set	Apply given CLI arg, but also force HANAMI_ENV value to propagate the choice
set	set	Who's gonna win?

This will be complicated to communicate and let people wrap their heads around.