Thread safe

[cathoderaymission]

Request to make TMDb3 thread safe.

I think one part requires not using one specific cache file but using a seperate file for each lookup.

Btw, awesome package! Thanks for your work.

[cathoderaymission]

For anyone else - I've worked around this with an ugly hack.

In addition to using locks for any type of search and on any object which calls a function eg:title.imdb, title.alternative_titles, etc. as these accesses use the built-in cache for reads/writes...

I modified put() and get() in the Cache class to save the data from an url request to a file with the filename being the hash of the url, and conversely to read that file on a get.