build: default to main branch (#179)

Author: JustinBeckwith

.kokoro/sync-triggers.sh

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 # This script ensures that a Cloud Build trigger exists for each non-root
-# cloudbuild.yaml file. Each is triggered on a push to master for any file
+# cloudbuild.yaml file. Each is triggered on a push to main for any file
 # changed in the directory containing that cloudbuild.yaml file.
 
 set -eo pipefail
@@ -28,7 +28,7 @@ fi
 project=$1
 
 # change this configuration for testing
-branch="master"
+branch="main"
 repoOwner="googleapis"
 repoName="testing-infra-docker"
 

node/12-puppeteer/Dockerfile

@@ -1,7 +1,7 @@
 FROM node:12
 
 # Taken from
-# https://github.com/GoogleChrome/puppeteer/blob/master/docs/troubleshooting.md#running-puppeteer-in-docker
+# https://github.com/GoogleChrome/puppeteer/blob/main/docs/troubleshooting.md#running-puppeteer-in-docker
 
 # See https://crbug.com/795759
 RUN apt-get update && apt-get install -yq libgconf-2-4