Bump ember-concurrency from 1.1.7 to 1.2.0

Bumps [ember-concurrency](https://github.com/machty/ember-concurrency) from 1.1.7 to 1.2.0.
- [Release notes](https://github.com/machty/ember-concurrency/releases)
- [Changelog](https://github.com/machty/ember-concurrency/blob/master/CHANGELOG.md)
- [Commits](machty/ember-concurrency@1.1.7...1.2.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package-lock.json

@@ -68,7 +68,7 @@
     "ember-cli-sri": "2.1.1",
     "ember-cli-uglify": "^3.0.0",
     "ember-click-outside": "^1.3.0",
-    "ember-concurrency": "^1.1.7",
+    "ember-concurrency": "^1.2.0",
     "ember-css-modules": "^1.3.1",
     "ember-data": "~3.19.0",
     "ember-disable-prototype-extensions": "^1.1.3",