Set the correct version for factory boy

Pipfile

@@ -12,7 +12,7 @@ ipdb = "*"
 coverage = "*"
 
 [packages]
-factory-boy = "*"
+factory-boy = "==2.11.0"
 wagtail_factories = {git = "https://github.com/mvantellingen/wagtail-factories.git",ref = "master"}
 django = "==2.0.6"
 whitenoise = "==4.0b4"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "97ff5ca56ac835d40353e34e32ec8333ccb23822bcf971644b7641429d9774e1"
+            "sha256": "d8df39d66268a0f11672ac294e723ba744027b3c7bf6a41dd1dc52eff1ac1a46"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -233,11 +233,11 @@
         },
         "factory-boy": {
             "hashes": [
-                "sha256:728df59b372c9588b83153facf26d3d28947fc750e8e3c95cefa9bed0e6394ee",
-                "sha256:faf48d608a1735f0d0a3c9cbf536d64f9132b547dae7ba452c4d99a79e84a370"
+                "sha256:3763ecabafb341df75b82f3a80c40747adef32d0288282c0c2db7a13e53c6944",
+                "sha256:d0f7209473312c99dfcf154069a1c559d83cfcae0979af43cf8779c9a9f645b3"
             ],
             "index": "pypi",
-            "version": "==2.12.0"
+            "version": "==2.11.0"
         },
         "faker": {
             "hashes": [