Reduce distro packages installed

It's not clear why all these packages are being installed.
They don't seem to relate to the service itself or the role's
requirements to run the service.

Change-Id: Icc7feffcc38174c2e35f16d2b65edae9e8d27b66

vars/redhat.yml

@@ -18,14 +18,7 @@
 cache_timeout: 600
 
 trove_distro_packages:
-  - gcc
-  - gcc-c++
-  - git
   - httpd
   - httpd-tools
-  - libxslt-devel
-  - mariadb
   - mod_wsgi
-  - python-devel
-  - python-pip
   - qemu-img

vars/ubuntu-16.04.yml

@@ -21,11 +21,4 @@ trove_distro_packages:
   - apache2
   - apache2-utils
   - libapache2-mod-wsgi
-  - git
-  - build-essential
-  - python-dev
-  - python-software-properties
-  - python-pip
-  - mysql-client
-  - libxslt1-dev
   - qemu-utils