DEV: add "WAIT_FOR_URL" env to smoke test

This allows you to wait up to N seconds for the smoke test url to come up
in some cases you want to kick off the smoke test prior to having the smoke
test env ready to accept connections

lib/tasks/smoke_test.rake

@@ -33,12 +33,31 @@ task "smoke:test" do
   dir = ENV["SMOKE_TEST_SCREENSHOT_PATH"] || 'tmp/smoke-test-screenshots'
   FileUtils.mkdir_p(dir) unless Dir.exists?(dir)
 
-  response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == 'https') do |http|
-    http.request(request)
+  wait = ENV["WAIT_FOR_URL"].to_i
+
+  success = false
+  code = nil
+  retries = 0
+
+  loop do
+    response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == 'https') do |http|
+      http.request(request)
+    end
+
+    success = response.code == "200"
+    code = response.code
+
+    if !success && wait > 0
+      sleep 5
+      wait -= 5
+      retries += 1
+    else
+      break
+    end
   end
 
-  if response.code != "200"
-    raise "TRIVIAL GET FAILED WITH #{response.code}"
+  if !success
+    raise "TRIVIAL GET FAILED WITH #{code}: retried #{retries} times"
   end
 
   results = +""