Rails DB Migration Error: relation already exists

I am getting an error when I try to migrate my db. I don't entirely remember how I got here, but I believe I:

1. created new branch, scaffolded 'Requests', db:migrated, switched back to master, and merged branch
2. created another branch, did some stuff, db:migrated, and everything was working fine.

3. pulled from heroku postgres database so i could test out if things worked with actual data. then tried db migrating, but gave me this error:

   rake db:migrate
   ==  CreateRequests: migrating =================================================
   -- create_table(:requests)
   NOTICE:  CREATE TABLE will create implicit sequence "requests_id_seq1" for serial column "requests.id"
   rake aborted!
   An error has occurred, this and all later migrations canceled:
   
   PG::Error: ERROR:  relation "requests" already exists
   : CREATE TABLE "requests" ("id" serial primary key, "title" character varying(255), "content" text, "category" character varying(255), "status" character varying(255), "requested_track_id" integer, "created_at" timestamp, "updated_at" timestamp) 
   

Any ideas?