Switch streaming to websockets

[Niek]

Fixes #157

Based on the work of https://github.com/timdorr/tesla-api/blob/master/lib/tesla_api/stream.rb

This switches the streaming API to Websockets, since the other simple HTTP streaming is deprecated and no longer working.

[mseminatore]

@Niek Thank you for this PR! Unfortunately the CI build did not succeed. Can you take a look and see if you can get a clean build? If so I can merge this in.

[Niek]

@mseminatore ah, I'm using yarn - that's why. I have added the changed package-lock.json
now.

[andeplane]

I guess we could for now just remove the test for the streaming as it doesn't seem like the mock server supports websockets at all apiaryio/api-blueprint#257

I too have this problem and would like to see a websockets implementation in this library :D

[mseminatore]

@andeplane Yes I will remove the test for old streaming. Working to get this PR merged.

[Niek]

@mseminatore let me know if you need any changes in this PR. As far as I have tested it's working fine.

[mseminatore]

@Niek ready to merge this PR. But I see that package-lock.json has moved in master since your PR. Sorry for that. Can you update the handlebars version from ^4.0.1 to ^4.1.2? You should be able to see this in the files diff.

[Niek]

@mseminatore I merged the master changes in my branch now - should be good to go

[coveralls]

Coverage decreased (-1.8%) to 91.228% when pulling 81e9ac9 on Niek:websockets into 9e9edd2 on mseminatore:master.

[bdaneshgar]

I'm still getting 502 gateway errors with model 3 as in #157