Charmed OSM: migration to CharmHub

Change-Id: I7dd740b0ed007360767998372f97c53b5269fdf4
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/prometheus/charmcraft.yaml b/installers/charm/prometheus/charmcraft.yaml
index 0a285a9..babeda8 100644
--- a/installers/charm/prometheus/charmcraft.yaml
+++ b/installers/charm/prometheus/charmcraft.yaml
@@ -34,4 +34,6 @@
           - arm64
 parts:
   charm:
-    build-packages: [git]
+    build-packages:
+      - git
+      - libffi-dev