SAOC 2020 Milestone 2 Week 3

[Robert Aron]

Update for week 3 of Milestone 2

Last week I managed to do the following tasks for #SAOC2020:
- created structs for files and comments
- add basic support(can't use all query params and all components 
of a request body yet) for copy, create, list, get, delete, 
update files and empty thrash.
- add basic support for create, get, delete and list comments

The plan for the next week is:
- improve the functions already implemented
- create structs/classes for requests body (FileReqBody and 
CommentReqBody)
- implement a function that can turn those classes into JSONValue
- add support for permissions[0]
- add support for replies[1](to a comment)

Milestone 1 updates: [2]
Milestone 2 week 1: [3]
Milestone 2 week 2: [4]

[0]: 
https://developers.google.com/drive/api/v3/reference/permissions
[1]: https://developers.google.com/drive/api/v3/reference/replies
[2]: 
https://forum.dlang.org/post/eaefvlbgikujonfjjzqi@forum.dlang.org
[3]: 
https://forum.dlang.org/post/jezqwzpeknpxhmqgkewe@forum.dlang.org
[4]: 
https://forum.dlang.org/post/kffvsmmxrkftxlbqklsd@forum.dlang.org