Improved installation instructions

I put the change onto develop myself...

On Thu, Oct 23, 2014 at 11:06 AM, Pavel Zdeněk <notifications@github.com>
wrote:

> In README.rst:
>
> >
> > -    pip install salsita-gitflow
> > +    pip install --allow-unverified rbtools --allow-external rbtools salsita-gitflow
> > +
> > +Subsequent updates can go simply
> > +
> > +    pip install -U salsita-gitflow
>
> I am getting lost in what should be the documentation fix. Nothing is
> correct apparently, maybe except the sudo note which wasn't mentioned yet.
> I don't understand pip, python, neither salsita-gitflow internal mechanics.
> I just wanted the doc to contain the real needed commands, because the
> current ones are not. So the least amount of work for both of us probably
> would be if you do the change yourself :)
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/salsita/gitflow/pull/3/files#r19266121>.
>