Update docstrings and methods in api.py.
Update docstrings and methods in api.py.

Update the references URL in the doctring with the new Twitter API doc.
Fix formatting for :allowed_param in the docstring.
Fix method for destroy endpoints (POST instead of DELETE).
tsablic/tweepy,zhenv5/tweepy,Choko256/tweepy,aganzha/tweepy,LikeABird/tweepy,wjt/tweepy,edsu/tweepy,tweepy/tweepy,elijah513/tweepy,damchilly/tweepy,tuxos/tweepy,obskyr/tweepy,vishnugonela/tweepy,raymondethan/tweepy,IsaacHaze/tweepy,kcompher/tweepy,kylemanna/tweepy,robbiewoods05/tweepy,techieshark/tweepy,sidewire/tweepy,arunxarun/tweepy,thelostscientist/tweepy,srimanthd/tweepy,svven/tweepy,sa8/tweepy,takeshineshiro/tweepy,aleczadikian/tweepy,yared-bezum/tweepy,awangga/tweepy,vivek8943/tweepy,vikasgorur/tweepy,conversocial/tweepy,iamjakob/tweepy,kskk02/tweepy,atomicjets/tweepy,hackebrot/tweepy,cogniteev/tweepy,truekonrads/tweepy,bconnelly/tweepy,rudraksh125/tweepy