Required changes for mariadb 10.3

Mysql-python is a deprecated package and fails to build currently.
Make use of mysqlclient as is a fork of mysql-python with many bug
fixes a python3 support.
percona xtrabackup doenst work with mariadb 10.3,
replaces to use mariadb-backup tool.
https://jira.mariadb.org/browse/MDEV-15774

Change-Id: Icefe3a77fb12d57c869521000d458e3f58435374

docker/barbican/barbican-base/Dockerfile.j2

@@ -27,7 +27,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
 
 {% set barbican_base_pip_packages = [
     '/barbican',
-    'MySQL-python',
+    'mysqlclient',
     'pastedeploy',
     'python-barbicanclient',
     'uwsgi'

docker/kolla-toolbox/Dockerfile.j2

@@ -81,7 +81,7 @@ ENV PATH {{ virtualenv_path }}/bin:$PATH
         'ansible==2.2.0.0',
         '"cmd2<0.9.0"',
         'influxdb',
-        'MySQL-python',
+        'mysqlclient',
         'os-client-config==1.29.0',
         'pbr==4.0.0',
         'pymongo',

docker/mariadb/Dockerfile.j2

@@ -14,7 +14,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
         'hostname',
         'mariadb',
         'mariadb-server-galera',
-        'percona-xtrabackup',
+        'mariadb-backup',
         'pv',
         'rsync',
         'tar'
@@ -31,7 +31,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
     {% else %}
         {% set mariadb_packages = mariadb_packages + [
             'mariadb-server',
-            'percona-xtrabackup'
+            'mariadb-client'
         ] %}
     {% endif %}
 {% endif %}

docker/openstack-base/Dockerfile.j2

@@ -320,7 +320,7 @@ RUN curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py \
         'kombu',
         'monotonic',
         'msgpack-python',
-        'MySQL-python',
+        'mysqlclient',
         'netaddr',
         'netifaces',
         'os-client-config',