[feature] Add websocket endpoint for all location updates #191

[dee077]

Implemented a new websocket endpoint 'location/all/' to handle updates for all locations simultaneously.

Fixes #191

Checklist

• [x] I have read the OpenWISP Contributing Guidelines.
• [x] I have manually tested the changes proposed in this pull request.
• [ ] I have written new test cases for new code and/or updated existing tests for changes to existing code.
• [ ] I have updated the documentation.

Reference to Existing Issue

Closes #191

Description of Changes

• New endpoint created ws/loci/location/all/
• Tests are pending

Screen Recording

Live Location Update Recording.webm

[coveralls]

coverage: 99.823% (+0.004%) from 99.819% when pulling 49e21c4741b6b6e5c264ed78999d7c6830dc5add on feature/191-new-ws-endpoint-for-all-location into b80853f521d5cb3df695e6f85a3fa7af3b58bb90 on master.