Re-add AMX adapter (fixed)

[nickjacob]

Thanks @patmmccann for pointing out the failing test in the master branch CI. Ran the browserstack tests locally before this PR; made a few changes to pass (remove flatMap, use of outerHTML, etc).

Type of change

• Bugfix
• New bidder adapter

Description of change

This is to address the failing browserstack tests in the last PR of AMX Adapter (which was merged). Fixes problems mentioned here #5455 and other failing tests

• test parameters for validating bids

{
  bidder: 'amx',
  params: {
    testMode: true,
    tagId: 'cHJlYmlkLm9yZw'
  }
}

• contact email of the adapter’s maintainer: prebid@amxrtb.com

• official adapter submission

• Docs repo PR: Add AMX RTB adapter documentation prebid.github.io#2065

[FilipStamenkovic]

Tests are failing:

FAILED TESTS:
  AmxBidAdapter
    buildRequests
      ✖ can build a banner request
        HeadlessChrome 83.0.4103 (Linux 0.0.0)
      AssertionError: expected { Object (av, vr, ...) } to deeply equal { av: false, aw: 300, ah: 250, tf: 0 }

      + expected - actual

       {
         "ah": 250
      -  "av": true
      +  "av": false
         "aw": 300
         "tf": 0
      -  "vr": false
       }
      
    at Context.<anonymous> (webpack:///test/spec/modules/amxBidAdapter_spec.js:192:47 <- test/test_index.js:97789:93)

      ✖ can build a video request
        HeadlessChrome 83.0.4103 (Linux 0.0.0)
      AssertionError: expected { Object (av, vr, ...) } to deeply equal { av: true, aw: 360, ah: 250, tf: 0 }

      + expected - actual

         "ah": 250
         "av": true
         "aw": 360
         "tf": 0
      -  "vr": true
       }
      
    at Context.<anonymous> (webpack:///test/spec/modules/amxBidAdapter_spec.js:210:58 <- test/test_index.js:97808:104)


10 07 2020 13:25:37.637:WARN [launcher]: ChromeHeadless was not killed in 2000 ms, sending SIGKILL.
[13:25:37] 'test' errored after 46 s
[13:25:37] Error: Karma tests failed with exit code 1
    at Prebid.js/gulpfile.js:279:12
    at removeAllListeners (Prebid.js/node_modules/karma/lib/server.js:370:9)
    at Prebid.js/node_modules/karma/lib/server.js:381:13
    at Server.close (net.js:1602:9)
    at Object.onceWrapper (events.js:421:28)
    at Server.emit (events.js:327:22)
    at Server.EventEmitter.emit (domain.js:505:15)
    at emitCloseNT (net.js:1655:8)
    at processTicksAndRejections (internal/process/task_queues.js:83:21)
[13:25:37] 'test' errored after 1.12 min

On your branch tests are passing, I had to copy your code and run tests on my local master branch.
Can you please pull/rebase latest changes from origin master?
I see your branch is, at the moment, 103 commits behind origin master, so in those 103 commits something was added/removed which is causing tests to fail on master and to pass on your branch.

[nickjacob]

Thank you @FilipStamenkovic -- I made the requested changes, rebased against upstream master & ran the tests in browserstack too

[FilipStamenkovic]

LGTM