SAOC 2020 Milestone 3 Week 1

[Robert Aron]

Update for week 1 of Milestone 3

Last week I managed to do the following tasks for #SAOC2020:
- removed unused imports
- added user defined attributes for reqbody classes
- improved bodyToJSON function:
     1. instead of converting all the fields, the function 
converts only those that are
        allowed for the operation executed. The fields that are 
used for an operation have
        its name as an attribute. For example, if I want to create 
a file, the function
        will convert only those fields that have the "create" 
attribute.
     2. created a filter that removes methods names from the 
members names list
     3. conversion of array of objects and SysTime
- replaced bool from reqbody with Nullable!bool, because I want 
to use the fields that are initialized by the user

The plan for the next week:
- code refactoring
- add unittests
- test the entire library

Milestone 1 updates: [0]
Milestone 2 week 1: [1]
Milestone 2 week 2: [2]
Milestone 2 week 3: [3]
Milestone 2 week 4: [4]
Code repo: [5]

[0]: 
https://forum.dlang.org/post/eaefvlbgikujonfjjzqi@forum.dlang.org
[1]: 
https://forum.dlang.org/post/jezqwzpeknpxhmqgkewe@forum.dlang.org
[2]: 
https://forum.dlang.org/post/kffvsmmxrkftxlbqklsd@forum.dlang.org
[3]: 
https://forum.dlang.org/post/yvbnsycuxqjfxghqajbu@forum.dlang.org
[4]: 
https://forum.dlang.org/post/jwasbvtjbofftybnsqro@forum.dlang.org
[5]: 
https://github.com/Robert-Aron293/SAoC---Google-APIs/tree/master/dlang-google-api-interact