Many fixes, replace `verlib` with `pkg_resources.parse_version`, guess package name added

* fix master branch (was broken after merge).
* fix tests (was broken after 'verlib' was added).
* remove `verlib` (does not supported anymore, see #33) and add `pkg_resources.parse_version` (pip use this, so it is already installed). So, tests fix was not so necessary.
* fix pip-review in the name of justice^W PEP8
* add package name guess with pypi/simple (it redirects on correct package page). For example, for package `factory-boy`:

Was:

    $ pip-review
    No update information found for factory-boy

Now:

    $ pip-review
    factory-boy==2.0.2 is available (you have 1.1.0)