Set up Zuul check pipeline

Fixed: translateselectedtext:3
Change-Id: Ifcb104b3f4985240a89b3e59e919fa2e950ce497
diff --git a/Makefile b/Makefile
index 79fce51..b2c9d49 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: node_deps clean_dist deps clean_deps serve_chromium release release_chromium_stable release_chromium_beta clean_releases clean
+.PHONY: node_deps clean_dist deps clean_deps serve_chromium release release_chromium_stable release_chromium_beta build_test_extension clean_releases clean
 
 .DEFAULT_GOAL := release
 WEBPACK := ./node_modules/webpack-cli/bin/cli.js
@@ -32,6 +32,11 @@
 	$(RELEASE_SCRIPT) -c beta -b chromium -f
 	rm -rf dist/chromium
 
+# Target to build the extension for webext lint in the Zuul Check Pipeline.
+build_test_extension: deps
+	$(WEBPACK) --mode production --env browser_target=chromium
+	$(RELEASE_SCRIPT) -c stable -b chromium -f
+
 clean_releases:
 	rm -rf out