swc-installation-test-2.py: Prefer pip to easy_install

For virtual-pypi-installer.  easy_install is part of Setuptools [1], which was
dead for several years.  The Distribute fork took over, but has since been
merged back into a revitalized Setuptools (since Setuptools v0.7 [2], tagged
on 2013-06-02 [3]).  Pip >= v1.4 actually requires a modern Setuptools, not
Distribute [4].  Pip also improves on easy_install [5], which does not
currently support uninstalling packages [6].

[1]: http://pythonhosted.org/setuptools/
[2]: http://pythonhosted.org/distribute/
[3]: https://bitbucket.org/pypa/setuptools/commits/tag/0.7
[4]: http://www.pip-installer.org/en/latest/installing.html#id6
[5]: http://www.pip-installer.org/en/latest/other-tools.html#easy-install
[6]:
http://pythonhosted.org/setuptools/easy_install.html#uninstalling-packages