virtualenv: allow tests to run properly on them

While going through the dependency list (requirements*.txt files) and
performing our self tests out of virtual environments, I noticed that
some tests are run outside the virtual environments.

The reason is that, even though the virtual environment is activated
for the test session (and say, `which python` gives `/venv/bin/python`),
we have hard coded `/usr/bin/python` in most places.

According to the some discussions on the virtualenv project itself[1],
a quick solution is to revert to the also common `/usr/bin/env python`
way of pointing to the Python interpreter.

[1] - https://github.com/pypa/virtualenv/issues/124Signed-off-by: NCleber Rosa <crosa@redhat.com>

Fix test providers checkout

Var "lbranch" was hard coded to "master", so it was never copied from var "branch".

"make check" needs pydot to run.

requirements-travis.txt: Require inspektor 0.2.0

Inspektor 0.2.0 has some improvements in the queue,
mainly now by default we are going to start being
picky on unused imports. Which is something I wanted
to do for a long time.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

avocado: Fixing unused imports

This was caught by modified inspektor check. I'm still
working on inspektor, meanwhile let's send this fix.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

requirements-travis.txt: Fix inspektor requirement problems

Require inspektor 0.1.19 to fix the pylint requirement
problems on python 2.6.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

avocado.utils.process: Improve detection to run cmd in GDB [v2]

shlex.split() can fail on some strange commands (eg. on an unfinished
quotation). This patch fallbacks to simple string.split() in such cases,
which might return incorrect results, but is safer to use. Although it
logs warning about this notifying the user about possible issue.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

It has been reported that avocado crashes when a malformed command
is attempted to be executed, even when using `shell=True`.

The reason is that `shlex.split` will raise `ValueError` on those
commands. Since improving `shlex.split` may be too complex, and
possibly not the best place to "fix" this, let's just assume safely
that this command should be run on GDB.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

README: Change the yum repository

The repository for Fedora/RHEL has changed.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

software_manager: Add --allow-unauthenticated to apt options

Sometimes we might add a repo that has no GPG keys and
still want to install a package from that repo. We need
--allow-unauthenticated to tell APT that we really want to install
it.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

avocado.core.remoter: Fix error on exception reference

fabric.network was never imported in avocado.core.remoter,
but fabric.network.NetworkError was referenced in its code,
making the exception to never actually be captured. Let's
fix it.

While at it, let's resolve one complaint of the pycharm
python checker: When importing some module on a try/except
block, make some effort to define the module in case of
failure.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Let's use comprehensions for generating pools and itertools to flatten
the list of variants. This improves the performance ~10%.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

Multiplex doc: attempt to reduce confusion on file format and line nu…

Miscellaneous fixes

Ideally our HTML formatted docs would have toggable line numbers. Since
we don't have that, let's just try to be clearer about the line numbers
not being part of the multiplex file format.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

This example file should have been remove together with commit
7b969527. Better late than never,
so let's do it now.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

Signed-off-by: NCleber Rosa <crosa@redhat.com>

Fix the docstring that doesn't reflect that the result parameter
should actually be a TestResultProxy.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Some tests might require additional cleanups not just after the test,
but after the whole job. This patch adds another message called
"func_at_exit", which can be pushed by the test and will get registered
and called when all tests finish.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

The test_status is handled in TestRunner.run_test quite chaotically.
This patch extracts test-related communication into a separate class,
and provides simple abstraction, making it simpler to extend it of
other messages.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

The current probe is not identifying the version numbers
for CentOS 7.X. Let's use a more relaxed regexp to fix
that problem.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

It turns out we forgot to state fabric dependencies in the
debian package. Let's fix that problem.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Let's remove an artifact from old times. The current
process APIs should handle stdout and stderr just fine.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Add the gdebi-core dependency that our ubuntu users might need
to if they are going to use the avocado software manager
library.
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

It turns out that apt doesn't really handle local installs
graciously as dnf/yum, but thankfully there is a program
named gdebi, shipped in Debian and Ubuntu, that would let
us do that. Use it when available (we can make gdebi a
dependency for the avocado debian package to ensure it'll
always be there).
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>

Fix the command used to check package status (there was
a missing space there) and the logic for checking installation
(verify OK string in the entire command output).
Signed-off-by: NLucas Meneghel Rodrigues <lookkas@gmail.com>