PSR-7 compatible HTTP stack

[magnusnordlander]

Hi!

Despite the lack of enthusiasm in #12 (ping @Nyholm), I've updated the library to use a PSR-7 compatible HTTP stack (namely HTTPlug) instead of the homegrown solution currently used.

This way applications can use standardized tools to log, profile or debug the HTTP requests sent using this library.

[kalaspuff]

Hey! Great work with the additions! We're sorry about the lack of replies on this library. As it's meant as a boilerplate to get going on an integration to Billogram, we wanted the lib to have no external dependencies.

We might be wrong thinking this way and as it seems that you (developers) want the lib to be more mature we'll make sure to include this PR for the next release. No active development is currently being done on the lib however, but we'll try to be more responsive- Maybe a more open project would be more suitable in the future!

[Nyholm]

Thank you for the response.

From my point of view: You do not need to do any active development. You just need to be the project manager. I and some other members of the community will do the heavy lifting.