A go at PATCH implementation

[akshendra]

Implementing PATCH with optional JSON Patch.

1. If the body is of type application/json. The patched value is computed by replacing the properties stored, using Object.assign
2. If the body is of type application/json-patch+json. The patched value is calculted by applying JSON Patch.

Added Dependency: fast-json-patch
Possible solution for #33

[bluzi]

Thanks again, I'll test it soon and merge it if all goes well

[Haaruun-I]

Any updates on this? It's ben 2 years