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: Id9bdfe2698085a1e1d02672f1269a808adf9c6d0
Partial-Bug: #1741634

defaults/main.yml

@@ -272,7 +272,6 @@ horizon_listen_ports:
 # horizon packages that must be installed before anything else
 horizon_requires_pip_packages:
   - virtualenv
-  - virtualenv-tools
   - python-keystoneclient # Keystoneclient needed to OSA keystone lib
   - httplib2
 

tasks/horizon_install.yml

@@ -151,9 +151,12 @@
     - horizon_get_venv | changed
 
 - name: Update virtualenv path
-  command: >
-    virtualenv-tools --update-path=auto --reinitialize {{ horizon_bin | dirname }}
+  shell: |
+    find {{ horizon_bin }} -name \*.pyc -delete
+    sed -si '1s/^.*python.*$/#!{{ horizon_bin | replace ('/','\/') }}\/python/' {{ horizon_bin }}/*
   when: horizon_get_venv | changed
+  tags:
+    - skip_ansible_lint
 
 - name: Create horizon link for venv
   file: