Replace virtualenv-tools by a script

virtualenv-tools has a bug which gets triggered in gates: it can't
change the shebang of a virtualenv python bin/ files if they
were generated with a virtualenv script whose shebang ends with
python2 instead of python.

Because we can't modify virtualenv-tools, we use shell scripts
instead.

Change-Id: Iafa7b6d43291fde11a1a072ce624474712ec99eb
Partial-Bug: #1741634

defaults/main.yml

@@ -530,7 +530,6 @@ nova_novnc_pip_packages:
 # nova packages that must be installed before anything else
 nova_requires_pip_packages:
   - virtualenv
-  - virtualenv-tools
   - python-keystoneclient # Keystoneclient needed to OSA keystone lib
   - httplib2
   - python-openstackclient

tasks/nova_install.yml

@@ -157,11 +157,13 @@
     - nova_get_venv | changed
 
 - name: Update virtualenv path
-  command: >
-    virtualenv-tools --update-path=auto --reinitialize {{ nova_bin | dirname }}
+  shell: |
+    find {{ nova_bin }} -name \*.pyc -delete
+    sed -si '1s/^.*python.*$/#!{{ nova_bin | replace ('/','\/') }}\/python/' {{ nova_bin }}/*
   when:
     - nova_get_venv | changed
   tags:
+    - skip_ansible_lint
     - nova-pip-packages
 
 - include: "consoles/nova_console_{{ nova_console_type }}_install.yml"