Make package installable through pip

[yanone]

Hello,

it would be great if the package could be installable via pip, either hosted on PyPI (voluntary) or at least from the repo directly. It would need a setup.py that has all the necessary information for pip.

Installation example via PyPI:
pip install hello_loopring

Installation example via repo:
pip install git+https://github.com/Loopring/hello_loopring

This way it could automatically be used as a dependency in other tools, such as trading frameworks.

Much of the code is currently unusable as-is.
Example 1: the REST API Endpoint that's hard-coded into the client isn't even a real domain: https://github.com/Loopring/hello_loopring/blob/loopring-v3/sdk/loopring_v3_client.py#L25
Example 2: the command line explorer isn't even usable as-is, because it can't import sdk from that folder structure.

Anyone wanting to use the code would need to download and tweak it. That's sad, when it can be made usable with hopefully just minor tweaks.

I could submit a PR if you like.

Thank you.