ci(kitchen): use `debian-10-master-py3` instead of `develop` [skip ci]

* Automated using https://github.com/myii/ssf-formula/pull/84

.cirrus.yml

   name: Test ${INSTANCE}
   env:
     matrix:
-      - INSTANCE: default-debian-10-develop-py3
+      - INSTANCE: default-debian-10-master-py3
       # - INSTANCE: default-ubuntu-1804-develop-py3
       # - INSTANCE: default-centos-7-develop-py3
       # - INSTANCE: default-fedora-30-develop-py3

kitchen.yml

 # Make sure the platforms listed below match up with
 # the `env.matrix` instances defined in `.travis.yml`
 platforms:
-  ## SALT `develop`
-  - name: debian-10-develop-py3
+  ## SALT `develop` => `master`
+  - name: debian-10-master-py3
     driver:
-      image: netmanagers/salt-develop-py3:debian-10
+      image: netmanagers/salt-master-py3:debian-10
       provision_command:
         - curl -o bootstrap-salt.sh -L https://bootstrap.saltstack.com
-        - sh bootstrap-salt.sh -XdPbfrq -x python3 git develop
+        - sh bootstrap-salt.sh -XdPbfrq -x python3 git master
   - name: ubuntu-1804-develop-py3
     driver:
       image: netmanagers/salt-develop-py3:ubuntu-18.04