Fedora: Update to 31, drop 29 and 30

Fedora 29 is deprecated.
Fedora 30 cannot be supported because of a bug in the gdbm package which
makes the tests break.
See also:
* exaile/exaile#626
* https://bugzilla.redhat.com/show_bug.cgi?id=1706639

Author: genodeftest

Dockerfile.fedora30

@@ -1,5 +1,5 @@
 
-FROM docker.io/fedora:29
+FROM docker.io/fedora:31
 MAINTAINER Dustin Spicuzza <dustin@virtualroadside.com>
 
 RUN true \

Dockerfile.fedora29 renamed to Dockerfile.fedora31

@@ -2,7 +2,7 @@
 
 cd `dirname $0`
 
-TOBUILD=${1:-debian9 debian10 fedora29 fedora30 ubuntu18.04 ubuntu19.10}
+TOBUILD=${1:-debian9 debian10 fedora31 ubuntu18.04 ubuntu19.10}
 BASE=docker.io/exaile/gst-python
 
 for i in ${TOBUILD}; do