Always install apache and proxy-uwsgi

We're going to want to start using it by default so just start with
always installing it. This should not negatively impact anything else.

Also had to fix the test using cowsay, now that cowsay depends on
cowsay-off.

Part of uwsgi in devstack.

Change-Id: I8306a992d9d006bc0130a255145a6880065aa0df
diff --git a/files/debs/general b/files/debs/general
index edf64ce..20490c6 100644
--- a/files/debs/general
+++ b/files/debs/general
@@ -1,3 +1,5 @@
+apache2
+apache2-dev
 bc
 bridge-utils
 bsdmainutils
@@ -9,6 +11,7 @@
 git
 graphviz # needed for docs
 iputils-ping
+libapache2-mod-proxy-uwsgi
 libffi-dev # for pyOpenSSL
 libjpeg-dev # Pillow 3.0.0
 libmysqlclient-dev  # MySQL-python