Drop Fedora 29 support

With fedora-latest now using Fedora 30 images and Fedora 29 itself EOL
we can now remove support for it from devstack. This change also cleans
up references to earlier Fedora releases under files/rpms/.

Change-Id: I24332f7016ebb549ea678acf677c477b55ec4d4b
diff --git a/files/rpms/nova b/files/rpms/nova
index 6c3e478..c590378 100644
--- a/files/rpms/nova
+++ b/files/rpms/nova
@@ -7,7 +7,7 @@
 genisoimage # required for config_drive
 iptables
 iputils
-kernel-modules # dist:f25,f26,f27,f28,f29,f30
+kernel-modules # dist:f30
 kpartx
 libxml2-python
 m2crypto