virt: Add a function to remove domain agent channel

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
Merge pull request #1608 from liyangfnst/agent

virt: Add a function to remove domain agent channel
virttest: Update qemu_io to use get_qemu_io_binary to get qemu_io_cmd

Use get_qemu_io_binary provide by utils_misc in qemu_io to ignore some
structure change problem from now on.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Merge pull request #1642 from ypu/qemu_io

virttest: Update qemu_io to use get_qemu_io_binary to get qemu_io_cmd
virttest: PEP8 Mass fix - part 1

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
virt-test: Fix PEP8 E714 errors

Tests for identity should take the form `is not None` rather
than `not is None`.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Mass Fix for PEP8 E112

Signed-off-by: Lucas Meneghel Rodrigues
virttest: Mass PEP8 fix for E713

E713: test for membership should be 'not in'

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
.travis.yml: Introduce PEP8 Checks

Let's start to complain on PEP8 violations. This is going
to be fun.

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