ci(travis): standardise saltcheck comments

* Automated using myii/ssf-formula#83

.travis.yml

@@ -16,8 +16,9 @@ script:
   # yamllint disable rule:line-length
   # Converge and verify the instance; `saltcheck` relies upon the `converge` as well
   - bin/kitchen verify "${INSTANCE}"
-  # If a `develop` instance, get the appropriate version of `saltcheck.py` &
-  # `cron.py` (temporary)
+  # If a `develop` instance, get the appropriate version of `saltcheck.py` (temporary)
+  # Likewise, use a custom `cron.py` temporarily until the upstream PR is merged:
+  # - https://github.com/saltstack/salt/pull/55016
   - if [ ! -z $(echo "${INSTANCE}" | grep \\-develop-) ]; then
       bin/kitchen exec "${INSTANCE}" -c
         "sudo curl -o \$(find /usr/lib/ -type d -name modules | grep packages/salt/modules)/saltcheck.py