lib/nitcorn: handles bufferized request content

Partially fixes #1027

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
lib/nitcorn: allows access to POST raw body

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
lib/json: introduces json store a simple json data storage system.

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
Merge branch 'json-store' into work
Merge branch 'nitcorn' into work
lib/github: introduces GithubCurl::get_and_parse to handle API error without aborting

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
lib/github: introduces object oriented interface for GithubAPI

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>