Remove mapboxgl.util.inherit

[lbud]

util.inherit was removed in mapbox/mapbox-gl-js@3995086. For now I've just copied that code here. Circle is being weird

and also these tests don't seem to be passing anyway (local test output:

> mapbox-gl-geocoder@1.3.1 lint /Users/laurenbudorick/src/mapbox-gl-geocoder
> eslint --no-eslintrc -c .eslintrc index.js src

TAP version 13
# geocoder
# initialized
ok 1 geocoder is initialized
# set/get input
ok 2 feature is present from get
ok 3 feature is in the event object
ok 4 center.lng changed
ok 5 center.lat changed
# options
ok 6 Event for results emitted
ok 7 center.lng is unchanged
ok 8 center.lat is unchanged
ok 9 one result is returned with expected place name
# options.bbox
ok 10 Event for results emitted
not ok 11 Result is returned within a bbox
  ---
    operator: equal
    expected: 'Paris Jewelry'
    actual:   'Parish of St. John the Baptist'
  ...
# options:zoom
not ok 12 Custom zoom is supported
  ---
    operator: equal
    expected: 12
    actual:   12.000000000000002
  ...
# fire
ok 13 should be equal
ok 14 event fires only once
# Geocoder#inputControl
# input
ok 15 should be truthy
ok 16 value populates in input
ok 17 clear link is active
ok 18 should be truthy
ok 19 clear link removed
ok 20 value populates in input
ok 21 clear link is active
ok 22 input is set but result is null
# position
ok 23 should be truthy
# placeholder
ok 24 placeholder is custom
# container
ok 25 appended to custom container
# shutdown

1..25
# tests 25
# pass  23
# fail  2

ping @tristen do you know anything about this?

[lbud]

Ooootay 👞 'ed this on CircleCI (ty @alulsh!), updated a test per chat with the geocoding gang. However, this isn't running on CircleCI because it is sad about WebGL. I started down the road of trying to work mapbox-gl-js-mock into this but interrupted myself by having to break all the 3D mapbox maps (both that breaking change and republishing mapbox-gl-geocoder are prerequisites for mapbox-gl-js v0.27.0).

Will come back to this once that's ready, unless anyone else is looking to do some CI browser trickery here 👻

[lbud]

I started down some 🐰🕳s of working in mapbox-gl-js-mock to get this running on CI, but before I get too deep in the weeds of that I think we're better off waiting for the gl-js Control refactor dust to settle (mapbox/mapbox-gl-js#3497 mapbox/mapbox-gl-js#2118 etc), so I'm going to do a Bad Thing here and just merge despite the ❌ (all tests passing locally). (Once that dust does settle I'll work on setting up CI for mapbox-gl-compare too.)
(cc @tristen)