Fix detection of HTML accept header so that requests for non-HTML resources can still get through to the proxy
Update CHANGELOG.md

Fixed typo
Merge pull request #1299 from quaertym/patch-1

Update CHANGELOG.md
Merge remote-tracking branch 'upstream/master' into fix-html-header-detection

* upstream/master:
  Update CHANGELOG.md
  add change log entry. Use populateLegacyFiles to populate test files
  use _processedVendorTree() instead of hardcoded 'vendor'
  remove deprecation warning
  move QUnit assets into test-vendor.js and test-vendor.css. Add type option to import to specify which that it's a test asset
  normalizeEntityName should be able to modify the entity name.
  Fix smoke test.
  Fix `app.import`'s behavior in addons.
  Coffee script support is provided by `ember-cli-coffeescript` addon.
  Update CHANGELOG.md
  Add UpdateTask test to check if package.json file gets updated with new version number
  [fixes #1265] don’t diverge the promise chains (we must wait for the update to occur)
  fix public folder deleted breaking build
  fixing changelog link
  Always use forward slash for vendor warning.
  update outdated deps
  Update CHANGELOG.md
  Update README.md
Add tests for proxy behaviour
Merge branch 'fix-html-header-detection'

* fix-html-header-detection:
  Add tests for proxy behaviour
  Update CHANGELOG.md
  Fix detection of HTML accept header so that requests for non-HTML resources can still get through to the proxy