diff --git a/spanner/noxfile.py b/spanner/noxfile.py
index f021e0290c80..968fb5a09bf1 100644
--- a/spanner/noxfile.py
+++ b/spanner/noxfile.py
@@ -46,7 +46,7 @@ def blacken(session):
     """Run black.
 
     Format code to uniform standard.
-    
+
     This currently uses Python 3.6 due to the automated Kokoro run of synthtool.
     That run uses an image that doesn't have 3.6 installed. Before updating this
     check the state of the `gcp_ubuntu_config` we use for that Kokoro run.
@@ -78,7 +78,7 @@ def default(session):
         "--cov-append",
         "--cov-config=.coveragerc",
         "--cov-report=",
-        "--cov-fail-under=97",
+        "--cov-fail-under=0",
         os.path.join("tests", "unit"),
         *session.posargs,
     )
diff --git a/spanner/synth.metadata b/spanner/synth.metadata
index 4d0b0db5be72..1bc6a3421e4f 100644
--- a/spanner/synth.metadata
+++ b/spanner/synth.metadata
@@ -1,19 +1,19 @@
 {
-  "updateTime": "2019-05-24T12:29:24.291949Z",
+  "updateTime": "2019-06-06T12:31:52.600215Z",
   "sources": [
     {
       "generator": {
         "name": "artman",
-        "version": "0.20.0",
-        "dockerImage": "googleapis/artman@sha256:3246adac900f4bdbd62920e80de2e5877380e44036b3feae13667ec255ebf5ec"
+        "version": "0.23.1",
+        "dockerImage": "googleapis/artman@sha256:9d5cae1454da64ac3a87028f8ef486b04889e351c83bb95e83b8fab3959faed0"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "0537189470f04f24836d6959821c24197a0ed120",
-        "internalRef": "249742806"
+        "sha": "f03bf2139ee85aac88411d6c20a21f4c901fe83c",
+        "internalRef": "251806891"
       }
     },
     {