Pull .env file from a git repository

* We've been having trouble with out of date
.env files.
* This will pull the .env file from
a git repository
Check if config files have changed

* If .env hasn't changed and user hasn't explicitly
said they want to replace it - don't.
* Also let the user set the name of the .env file. This
is something I'm using for testing (so I don't blow away
an existing .env with a test .env
Code review changes

* Namespaced everything under :environment:servers
and :environment:local
Ask for .env override at the beginning of task

* As per @RyanonRails request
* In case the remote config repo is unreachable
from the server you're deploying to
Strip trailing newlines from Campfire speaker

* Before we were using 'whoami' now we are
using 'git config user.name' which returns
a newline character at the end
Merge pull request #9 from amaabca/fetch-env-from-git-repo

Fetch env from git repo