Update the kokoro config (#199)

Author: dpebot

handwritten/datastore/.circleci/npm-install-retry.js

@@ -6,7 +6,7 @@ let spawn = require('child_process').spawn;
 //USE: ./index.js <ms npm can be idle> <number of attempts> [... NPM ARGS]
 //
 
-let timeout = process.argv[2] || 60000;
+let timeout = process.argv[2] || process.env.NPM_INSTALL_TIMEOUT || 60000;
 let attempts = process.argv[3] || 3;
 let args = process.argv.slice(4);
 if (args.length === 0) {

handwritten/datastore/.kokoro/presubmit/node8/samples-test.cfg

@@ -0,0 +1,7 @@
+# Download resources for system tests (service account key, etc.)
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-nodejs"
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/nodejs-datastore/.kokoro/samples-test.sh"
+}

handwritten/datastore/.kokoro/presubmit/node8/system-test.cfg

@@ -0,0 +1,7 @@
+# Download resources for system tests (service account key, etc.)
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-nodejs"
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/nodejs-datastore/.kokoro/system-test.sh"
+}