fix(reputation): error 500 when empty result

[HugoDelval]

Also change shebang from /bin/sh -> /bin/bash and improve Readme

The error 500 was happening because in python:

if not []:
    return 500
else:
    return 200

returns 500

[coveralls]

Coverage remained the same at 63.589% when pulling 485a9f7 on HugoDelval:master into 3c4a908 on ovh:master.

[HugoDelval]

Closing this PR in favor of a bigger PR on the dev branch here -> #13