utils_test: Add two functions for libvirt tests

Function to check virsh commands exit status.
Function to check interface for virsh iface related tests.

Signed-off-by: Yanbing Du <ydu@redhat.com>

Conflicts:
	virttest/utils_test/libvirt.py
virttest.virsh: Add wrappers for iface related commands

Signed-off-by: Yanbing Du <ydu@redhat.com>
Typo fix

Signed-off-by: Yanbing Du <ydu@redhat.com>
Merge pull request #1587 from will-Do/iface

Add iface related commands wrappers and libvirt common test functions
.travis.yml: Tidy up requirements.txt and force pylint 1.0

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
documentation: .rst fixes

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
virttest: Docstring fixes

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
virttest.utils_test: Create generic module

Instead of having a ton of code in utils_test.__init__,
let's create a ``generic`` module and import its
functions in __init__. This will avoid pylint
breaking in weird ways.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>