bring back oslo_clean

oslo_clean is still needed at this point, removing it was
premature, especially for upgrade testing.

Change-Id: Ic845d835f587923423f83ac698bd825f3fa5dd1f
diff --git a/lib/oslo b/lib/oslo
index 2e1f6bf..3cf7218 100644
--- a/lib/oslo
+++ b/lib/oslo
@@ -34,6 +34,10 @@
 
 # install_oslo() - Collect source and prepare
 function install_oslo {
+    # TODO(sdague): remove this once we get to Icehouse, this just makes
+    # for a smoother transition of existing users.
+    cleanup_oslo
+
     git_clone $CLIFF_REPO $CLIFF_DIR $CLIFF_BRANCH
     setup_install $CLIFF_DIR
 
@@ -59,6 +63,17 @@
     setup_install $TASKFLOW_DIR
 }
 
+# cleanup_oslo() - purge possibly old versions of oslo
+function cleanup_oslo {
+    # this means we've got an old oslo installed, lets get rid of it
+    if ! python -c 'import oslo.config' 2>/dev/null; then
+        echo "Found old oslo.config... removing to ensure consistency"
+        local PIP_CMD=$(get_pip_command)
+        pip_install oslo.config
+        sudo $PIP_CMD uninstall -y oslo.config
+    fi
+}
+
 # Restore xtrace
 $XTRACE