Reworked site regression test suite to serverless boot

refs https://github.com/TryGhost/Toolbox/issues/152

- Being able to set up test suites without blocking a port opens a door to new ways to run tests - for example this has been one of the blockers for running mocha tests in parallel
- Additional benefit is lighter statrup, which reducec the test execution time slightly. Doesn't seem like much but these things stack up!

test/regression/api/canary/admin/site.test.js

@@ -8,8 +8,8 @@ describe('Config API', function () {
     let request;
 
     before(async function () {
-        await localUtils.startGhost();
-        request = supertest.agent(config.get('url'));
+        const app = await localUtils.startGhost();
+        request = supertest.agent(app);
         await localUtils.doAuth(request);
     });
 

test/utils/e2e-utils.js

@@ -137,10 +137,6 @@ const restartModeGhostStart = async ({frontend}) => {
     limits.init();
 };
 
-const bootGhost = async ({backend, frontend}) => {
-    ghostServer = await boot({backend, frontend});
-};
-
 // CASE: Ghost Server needs Starting
 // In this case we need to ensure that Ghost is started cleanly:
 // - ensure the DB is reset
@@ -166,7 +162,11 @@ const freshModeGhostStart = async (options) => {
     await settingsService.init();
 
     // Actually boot Ghost
-    await bootGhost(options);
+    ghostServer = await boot({
+        backend: options.backend,
+        frontend: options.frontend,
+        server: options.server
+    });
 
     // Wait for the URL service to be ready, which happens after boot
     if (options.frontend) {