build(test): recursively find test files; fail on unsupported depende…

…ncy versions (#510)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/396d1a63-c8ed-42ae-811f-d2b08d6e2089/targets

- [ ] To automatically regenerate this PR, check this box.

Source-Link: googleapis/synthtool@fdd03c1

packages/google-cloud-language/.mocharc.js

@@ -14,7 +14,8 @@
 const config = {
   "enable-source-maps": true,
   "throw-deprecation": true,
-  "timeout": 10000
+  "timeout": 10000,
+  "recursive": true
 }
 if (process.env.MOCHA_THROW_DEPRECATION === 'false') {
   delete config['throw-deprecation'];

packages/google-cloud-language/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-language.git",
-        "sha": "df948affcc41bc6cf171bda6e3834db32fa22aa3"
+        "sha": "3ab34d3d464b66948c616b1f00dae061a48e57e3"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "8cf6d2834ad14318e64429c3b94f6443ae83daf9"
+        "sha": "fdd03c161003ab97657cc0218f25c82c89ddf4b6"
       }
     }
   ],