test: Add a browser based test harness (#2641)

scripts/release-version.js

@@ -0,0 +1,12 @@
+/**
+ * The literal the card carries in place of its version, for the build to
+ * rewrite.
+ *
+ * `getReleaseVersion` cannot import this: it has to sit in that source as a
+ * plain string for the build to have something to replace. It lives in its own
+ * module because the build, the browser tests and a unit test all have to agree
+ * on it, and none of them should have to depend on either of the others.
+ *
+ * It must be in a JS file as Node's loader cannot import TypeScript.
+ */
+export const RELEASE_VERSION_TOKEN = '__ADVANCED_CAMERA_CARD_RELEASE_VERSION__';