CYB-377 Youtube URLs are not always https

* changed the regular expression where it matched the protocol to always match
    http:// or https://
* This will ensure that Youtube videos are handled as such.

[CYB-377 Youtube URLs are not always https](https://jira.ets.berkeley.edu/jira/browse/CYB-377)
These regular expressions don't seem to be covering all of the possible Youtube and Vimeo URLs (e.g. `youtu.be`, `/watch`, etc.). Can you swap it out for the regular expressions below?

Youtube: 

```
/^.*((youtu.be\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\?))\??v?=?([^#\&\?]*).*/
```

Vimeo:

```
/^.*(vimeo\.com\/)((channels\/[A-z]+\/)|(groups\/[A-z]+\/videos\/))?([0-9]+)/
```