Remove pip freeze logic

Tox 2.4 will do this today by default:

  http://tox.readthedocs.io/en/latest/config.html#confval-list_dependencies_command

It also means it is much easier for tox jobs to change pip freeze to
some other command (eg: pbr freeze).

Change-Id: I862a783500c46db99ac0971c88631764a2f982f2
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

roles/tox/tasks/main.yaml

@@ -6,9 +6,7 @@
   shell: |
     # If a bundle file is present, call tox with the jenkins version of
     # the test environment so it is used.  Otherwise, use the normal
-    # (non-bundle) test environment.  Also, run pbr freeze on the
-    # resulting environment at the end so that we have a record of exactly
-    # what packages we ended up testing.
+    # (non-bundle) test environment.
 
     venv={{ tox_envlist }}
 
@@ -19,15 +17,6 @@
         exit 1
     fi
 
-    function freeze_venv {
-        [ -e $bin_path/pbr ] && freezecmd=pbr || freezecmd=pip
-
-        echo "Begin $freezecmd freeze output from test virtualenv:"
-        echo "======================================================================"
-        ${bin_path}/${freezecmd} freeze | sort -f
-        echo "======================================================================"
-    }
-
     function process_testr_artifacts {
         if [ ! -d ".testrepository" ] ; then
             return
@@ -93,7 +82,6 @@
     tox -vv -e$venv
     result=$?
 
-    freeze_venv
     process_testr_artifacts
     check_oom
     check_nose_html