Added protocol-specific decorators and multiple improvements

See readme

Revamped way to add "original_message"

Fix some bugs.

Remove deprecated function for python> 3.5

1.1.5

version 1.1.5

1.1.4

Fix original_message not being thread-safe

1.1.3

Possibility to add json decoder

1.1.2

version 1.1.2

- Prevent test failures
- decorated rpc_method wrapper is compliant to decorator signature (for sphinx doc)

0.1.3

Added slack to Travis