Removed unneeded dependencies from elpy.rcp.

recipes/elpy.rcp:
        Removed iedit.rcp as, while useful, this package is not
        required in any way for elpy to function.

        Removed nose.rcp, as the elpy nose.rcp installs a emacs
        front-end for the nose python library. Elpy uses the nose python
        library directly so it does not require this front-end.

        Removed jedi.rcp, as the jedi front-end for emacs is not
        required for elpy. elpy uses the jedi python library directly.

        Actual dependencies for elpy can be viewed in
        https://github.com/jorgenschaefer/elpy/blob/master/elpy-pkg.el
        located in the elpy repo.