fix(centos7): add correct pymysql package on cent7/saltpy3

.yamllint

@@ -20,6 +20,7 @@ ignore: |
   .kitchen/
   kitchen.vagrant.yml
   mysql/supported_sections.yaml
+  mysql/osfingermap.yaml
 
 yaml-files:
   # Default settings

mysql/osfingermap.yaml

@@ -62,7 +62,11 @@ CentOS-6:
   pythonpkg: MySQL-python
 CentOS Linux-7:
   # https://mariadb.com/blog/rhel7-transition-mysql-mariadb-first-look
+      {%- if 'pythonversion' in grains and grains.pythonversion[0]|int == 3 %}
+  pythonpkg: python36-PyMySQL   # python36-mysql works too
+      {%- else %}
   pythonpkg: MySQL-python
+      {%- endif %}
   serverpkg: mariadb-server
   service: mariadb
   clientpkg: mariadb