Changed implementation of proxy setup

Changed the setup_http_proxy method to setup_proxy.
The same arguments are used as before. This change includes
workarounds for pulp proxy configuration. Example usage below.

PROXY_INFO=proxy://admin:p@$$w0rd@my.proxy.redhat.com:8888 fab -H some.random.machine.redhat.com -u root -p 'myP@$$w0rd1$$0c00l' setup_proxy
Merge pull request #57 from JacobCallahan/setup_proxy

Changed implementation of proxy setup
Add performance_tuning task

The task tunes up the Satellite 6 performance on both bare metal machine
and virtual machine according to the running_on_vm argument.
Merge pull request #58 from elyezer/performance-tuning

Add performance_tuning task
Increase poll subscribe retries

Automation matrix have increased and the poll subscribe is failing again
due to the concurrent subscription. Because this is better to increase
to a higher number to make sure all machines gets subscribed to the
poll.
Merge pull request #59 from elyezer/subscribe-retries

Increase poll subscribe retries
Make distro_info return an integer for version

Make distro_info task return an integer for os version.

Also fix os version check when checking if should install abrt plugin or
not on the provision_install task.
Merge pull request #60 from elyezer/fix-distro-info

Make distro_info return an integer for version
Fix typo on distro_info's docstring
Merge pull request #61 from elyezer/docstring-typo

Fix typo on distro_info's docstring