add dumb captcha to reduce signup spam problems

src/bornhack/forms.py

@@ -0,0 +1,16 @@
+from django import forms
+from django.core.exceptions import ValidationError
+
+
+class AllAuthSignupCaptchaForm(forms.Form):
+    first_bornhack_year = forms.CharField(
+        initial="",
+        help_text="Please help us prevent a few bot signups by telling us the year of the first BornHack.",
+    )
+
+    def clean_first_bornhack_year(self):
+        if self.cleaned_data["first_bornhack_year"] != "2016":
+            raise ValidationError("To error is human. Please try to be less human! :)")
+
+    def signup(self, request, user):
+        user.save()

src/bornhack/settings.py

@@ -198,3 +198,6 @@ ECONOMY_TEAM_NAME = "Economy"
 
 # we have some large formsets sometimes
 DATA_UPLOAD_MAX_NUMBER_FIELDS = 5000
+
+# use captcha form
+ACCOUNT_SIGNUP_FORM_CLASS = "bornhack.forms.AllAuthSignupCaptchaForm"