Use environment variables for proxy address

.github/workflows/main.yml

@@ -28,3 +28,4 @@ jobs:
           molecule test --all
         env:
           MOLECULE_DISTRO: ${{ matrix.molecule_distro }}
+          EPEL_MIRROR_URL: https://pproxy.guise.net.nz

molecule/mirror-is-set/converge.yml

@@ -7,4 +7,4 @@
         name: "{{ lookup('env', 'MOLECULE_PROJECT_DIRECTORY') | basename }}"
       vars:
         epel_specify_mirror: true
-        epel_mirror_url: https://pproxy.guise.net.nz
+        epel_mirror_url: "{{ lookup('env', 'EPEL_MIRROR_URL')"

molecule/mirror-is-set/verify.yml

@@ -22,4 +22,4 @@
   - name: mirror is specified correctly
     assert:
       that:
-        - "'https://someproxyormirror.org.nz' in repofile.stdout"
+        - "{{ lookup('env', 'EPEL_MIRROR_URL') in repofile.stdout"