added POST/GET for video

added views/urls

fixed for pr

removed a line

changed lookup field to edx_video_id

switch validators from serializer to models

regex validator for edx_video_id

minor edits

upgrade DRF. Added view test

added notes

GET test

more tests, handles many dicts

sends back invalids

some doc

last statment for post

test fix

another test

some doc

Partial creation, now updates existing objects

client_title -> client_video_id

POST now updates existing object

tidy up for PR