bug 1540655: remote: connect Puppeteer spec tests with mach test flavour; r=remote-protocol-reviewers,jdescottes

This makes it possible to for mach to determine which test types
are likely to be relevant.

Differential Revision: https://phabricator.services.mozilla.com/D37014

--HG--
extra : moz-landing-system : lando

remote/test/moz.build

@@ -4,3 +4,6 @@
 
 XPCSHELL_TESTS_MANIFESTS += ["unit/xpcshell.ini"]
 BROWSER_CHROME_MANIFESTS += ["browser/browser.ini"]
+
+with Files("puppeteer/test/**/*.spec.js"):
+    IMPACTED_TESTS.flavors += ["puppeteer"]