Remove duplicated/outdated disabled-payments tests from test_models

After ea421198e4f701343cff751ffa926095446ade4a this is covered in
mkt.search.tests.test_views
don't override the `index` variable from the function definition

index was set to `amo_stats` after the first loop iteration, and then didn't
get updated correctly to `amo` for the InappPayment model
Fix reviewer tools JS error

There are so many things wrong with this that I don't even want to
look at the `git blame`.
Merge pull request #678 from hannosch/852133-inapp-payments-wrong-es-template

don't override the `index` variable from the function definition
Merge pull request #679 from hannosch/764826-fix-es-tests

Remove duplicated/outdated disabled-payments tests from test_models
show settings gear (not cancel X) for non-retina people (bug 852178)
consolidated headers on ecosystem/devreg (bug 840253)