feat(cron.env): add env option in cron-formula

pillar.example

@@ -35,3 +35,19 @@ cron:
       minute: '*/5'
       hour: '*'
       comment: comment4
+  env:
+    env1:
+      type: present  # Default
+      name: PATH
+      value: /usr/local/bin:/usr/bin:/bin:/usr/games
+      user: root  # Default
+    env2:
+      type: absent
+      name: MAILTO
+      value: example@example.com  # not needed
+      user: root  # Default
+    env3:
+      type: absent
+      name: LANG
+      value: en_GB.UTF-8
+      user: root