Rename all test files from JS -> ES6

test/javascripts/components/select-kit/notifications-button-test.js.es6

@@ -1,40 +0,0 @@
-import componentTest from "helpers/component-test";
-import { testSelectKitModule, setDefaultState } from "./select-kit-test-helper";
-
-testSelectKitModule("notifications-button");
-
-componentTest("default", {
-  template: `
-    {{notifications-button
-      value=value
-      options=(hash
-        i18nPrefix=i18nPrefix
-        i18nPostfix=i18nPostfix
-      )
-    }}
-  `,
-
-  beforeEach() {
-    this.set("value", 1);
-
-    setDefaultState(this, 1, { i18nPrefix: "pre", i18nPostfix: "post" });
-  },
-
-  async test(assert) {
-    assert.ok(this.subject.header().value());
-
-    assert.ok(
-      this.subject
-        .header()
-        .label()
-        .includes(`${this.i18nPrefix}.regular${this.i18nPostfix}`),
-      "it shows the regular choice when value is not set"
-    );
-
-    const icon = this.subject.header().icon()[0];
-    assert.ok(
-      icon.classList.contains("d-icon-d-regular"),
-      "it shows the correct icon"
-    );
-  }
-});