Add websocket header support to the ROS-client

[TheSpeedM]

Description

Some device that I am using has a websocket available that is protected with a token. This token needs to be passed via the websocket connection header. This PR adds websocket header support to the ROS-client.

The headers can be added to the ROS-client like this, also see test_ws_headers.py:

headers = {
    'cookie': 'token=rosbridge',
    'authorization': 'Some auth'
}

client = Ros('127.0.0.1', 9000, headers=headers)

What type of change is this?

• Bug fix in a backwards-compatible manner.
• New feature in a backwards-compatible manner.
• Breaking change: bug fix or new feature that involve incompatible API changes.
• Other (e.g. doc update, configuration, etc)

I don't see a reason why this couldn't be backwards compatible, but I could be wrong.

Checklist

• I added a line to the CHANGELOG.rst file in the Unreleased section under the most fitting heading (e.g. Added, Changed, Removed).
• I ran all tests on my computer and it's all green (i.e. invoke test).
• I ran lint on my computer and there are no errors (i.e. invoke check).
• I have added tests that prove my fix is effective or that my feature works.
• I have added necessary documentation (if appropriate)

Questions

• Is this desired for this library? Otherwise I will continue to use my fork.
• Is the test in the right spot? It is independent of ROS-version so this seemed fine.
• I am not familiar with autobahn and twisted so let me know if this should be accomplished in another way.
• Should the passing of headers be more explicit? Now it just happens via the **kwargs of RosBridgeClientFactory.

[gonzalocasas]

Cool! Thanks!

[TheSpeedM]

Hi @gonzalocasas, any update on getting this merged?

[Elian0213]

Hi @gonzalocasas is this going to get merged? I had to pull his repository seperately in order to get this functionality working.

[gonzalocasas]

Sorry it took me so long! it lgtm! I'll merge and release today

[Elian0213]

Sorry it took me so long! it lgtm! I'll merge and release today

Hell yeah!

[gonzalocasas]

@TheSpeedM @Elian0213 the release is already available on pip, will land on conda-forge a bit later today/early tomorrow