Add open-collective to funding file

.github/FUNDING.yml

@@ -2,11 +2,4 @@
 
 github: [pydanny, browniebroke]
 patreon: feldroy
-open_collective: # Replace with a single Open Collective username
-ko_fi: # Replace with a single Ko-fi username
-tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
-community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
-liberapay: # Replace with a single Liberapay username
-issuehunt: # Replace with a single IssueHunt username
-otechie: # Replace with a single Otechie username
-custom: ["https://www.patreon.com/browniebroke"]
+open_collective: cookiecutter-django