Add ReCaptcha to petition sign form

petitions/forms.py

 from django import forms
 
+from captcha.fields import ReCaptchaField
+
 from .models import PetitionSignatory
 
 
 class SignPetitionForm(forms.ModelForm):
+    captcha = ReCaptchaField(attrs={'theme': 'clean'}, label='*Please verify to continue:')
+
     class Meta:
         model = PetitionSignatory
         fields = ['title', 'first_name', 'last_name',