Update acquia_purge to 7.x-1.4-beta2

[janette]

https://www.drupal.org/project/acquia_purge/issues/2155319 New version supports clearing wildcard URL's

• [ ] Update build.make with acquia_purge version 7.x-1.4-beta2
• [ ] Remove ape from features master (keep it in build.make for now, we will just keep it disabled by default)
• [ ] Add hook update to clear out ape config from db if not enabled
• [ ] Update default config

Acceptance Criteria

Cache is cleared when content changes.

[acouch]

I created a dupe. Closing that one: https://github.com/NuCivic/dkan_management/issues/85

[erogray]

Probably destined for 1.15.2

[dafeder]

Reopening the management ticket, closing this one as dkan_starter is being retired.