Logic to upload formulas to an environment is necessary

[Gustavo Niemeyer]

We need to implement some kind of formula.EnvironmentPublisher which is able to do the following:

1) Is initialized with an Environment instance

2) One or more formulas are added to it (e.g. publisher.add_formula(formula))

3) On publisher.publish(), a connection is established with the environment and:
    a) A verification is made to see which of the added formulas do not exist in the environment yet
    b) All the unavailable formulas are sent to the FileStorage of the given environment
    c) The new formulas are added to the Zookeeper filesystem, through the FormulaStateManager object (see bug #616481).

This logic would be used by the "deploy" command, but can also be used by an individual subcommand which is able to *just* upload the formula. Something like:

    $ ensemble store-formula <formula name>