Bug 1525923 - Fix version ranges for Dependabot ignored_updates (#4582)

Since it turns out the `ignored_updates` setting refers to the versions
that should be ignored, rather than the versions that are safe (which is
the opposite of pyup).

.dependabot/config.yml

@@ -14,27 +14,27 @@ update_configs:
       # and the update is blocked on resolving bug 1337717.
       - match:
           dependency_name: "celery"
-          version_requirement: "<4"
+          version_requirement: ">=4"
       - match:
           dependency_name: "kombu"
-          version_requirement: "<4"
+          version_requirement: ">=4"
       - match:
           dependency_name: "amqp"
-          version_requirement: "<2"
+          version_requirement: ">=2"
       - match:
           dependency_name: "billiard"
-          version_requirement: "<3.4"
+          version_requirement: ">=3.4"
       # Django 2 requires Python 3 (bug 1426683)
       - match:
           dependency_name: "Django"
-          version_requirement: "<2"
+          version_requirement: ">=2"
       # django-filter 2 requires Python 3 (bug 1489212)
       - match:
           # Bug 1426683
           dependency_name: "django-filter"
-          version_requirement: "<2"
+          version_requirement: ">=2"
       # Django 1.11 uses internals of mysqlclient that were removed in 1.3.14.
       # Newer mysqlclient only works with Django 2+ (bug 1517253).
       - match:
           dependency_name: "mysqlclient"
-          version_requirement: "<1.3.14"
+          version_requirement: ">=1.3.14"