modernize addon

[0xadada]

This addon could use some modernization luvin 💖:

• convert sendAction to closure actions sendAction deprication #50
• remove dependency on jQuery remove implicit dependencies on jQuery #55
• convert to use latest Ember LTS (3.8)
• use prettier to standardize and enforce code style Prettier #56
• convert addon to allow consumption via angle bracket syntax
• convert addon to use native ES classes

[oskarrough]

• upgrade ember concurrency Allowing to use newer versions of ember-concurrency. #58

[oskarrough]

Hey, I'm very sorry this never got merged. Are you still interested in it? I don't have any capacity to look at it I'm afraid.