Fix dir bug that caused redis to fail every write

`dir` config var should be set, and all data is relative to it.

* CF http://redis.io/topics/quickstart
* CF https://github.com/antirez/redis/issues/305
Add support for virtualenv prompt
Merge pull request #113 from vperron/master

Fix redis module DB persistency issue
Add redis persistence test [#113]
Upgrade default Redis version to 2.6.13
Merge pull request #115 from artnez/virtualenv-prompt

Add support for virtualenv --prompt option
add git support for repository cloning
add git support for repositiory maintenance
add repository to require module
debug wrong imports
put right import into contrib
add/improve comment for require repository file
add repository module to __init__ file
rename remote variable in the repository update function
Merge branch 'feature/git-support' of github.com:frankrousseau/fabtools into feature/git-support