Install gettext from apt on Trusty (Ubuntu 14.04)

The binary 'msgfmt' is not installed as part of python-gettext for Trusty
(Ubuntu 14.04), so gettext needs to be installed from apt.

Change-Id: I415814559d82be453e978a0d92a0cdb38f105683
Closes-Bug: 1331328
diff --git a/files/apts/heat b/files/apts/heat
new file mode 100644
index 0000000..1ecbc78
--- /dev/null
+++ b/files/apts/heat
@@ -0,0 +1 @@
+gettext # dist:trusty