Use temporary directory for neutron install

Do not install in /tmp/openstack/neutron and leave the git repository
there after the script is run - if zuul-cloner is used.

We run jobs on long lived workers and also on developers machines, let's
cleanup afterwards.

Install into a temporary directory that can be removed with "git clean"
afterwards. Add this directory to ignore list of pep8.

Simplify with using pushd/popd which are bash features, so change
she-bang.

Also, remove setup of ZUUL_BRANCH, this is not needed with current zuul
anymore.

Change-Id: I54d400dea4efdf9ac9b580ff7f0a2bbcceb4df5e

tools/tox_install.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 # Many of neutron's repos suffer from the problem of depending on neutron,
 # but it not existing on pypi.
@@ -26,10 +26,13 @@ if [ $neutron_installed -eq 0 ]; then
     echo "ALREADY INSTALLED" > /tmp/tox_install.txt
     echo "Neutron already installed; using existing package"
 elif [ -x "$ZUUL_CLONER" ]; then
-    export ZUUL_BRANCH=${ZUUL_BRANCH-$BRANCH}
     echo "ZUUL CLONER" > /tmp/tox_install.txt
-    cwd=$(/bin/pwd)
-    cd /tmp
+    # Make this relative to current working directory so that
+    # git clean can remove it. We cannot remove the directory directly
+    # since it is reference after $install_cmd -e.
+    mkdir -p .tmp
+    NEUTRON_DIR=$(/bin/mktemp -d -p $(pwd)/.tmp)
+    pushd $NEUTRON_DIR
     $ZUUL_CLONER --cache-dir \
         /opt/git \
         --branch $BRANCH_NAME \
@@ -37,7 +40,7 @@ elif [ -x "$ZUUL_CLONER" ]; then
         openstack/neutron
     cd openstack/neutron
     $install_cmd -e .
-    cd "$cwd"
+    popd
 else
     echo "PIP HARDCODE" > /tmp/tox_install.txt
     if [ -z "$NEUTRON_PIP_LOCATION" ]; then

tox.ini

@@ -52,7 +52,7 @@ commands = python setup.py build_sphinx
 ignore = E125,E126,E128,E129,E265,H404,H405,N524,N530
 show-source = true
 builtins = _
-exclude = .venv,.git,.tox,dist,doc,*lib/python*,*egg,build,tools,.ropeproject,rally-scenarios,neutron_lbaas/tests/tempest/lib,neutron_lbaas/tests/tempest/v1/api
+exclude = .venv,.git,.tox,dist,doc,*lib/python*,*egg,build,tools,.tmp,.ropeproject,rally-scenarios,neutron_lbaas/tests/tempest/lib,neutron_lbaas/tests/tempest/v1/api
 
 [hacking]
 import_exceptions = neutron_lbaas._i18n