fix: lerna publish script

[sobolk]

Description of changes

Fixes lerna publish script to explicitly exit when ERR! happens.

Issue #, if available

Description of how you validated changes

1. This PR's build and e2e tests job (this does run publish to verdaccio).

2. Tested added snippet with faked error.

bcd0740fa72c:~ sobkamil$ nano test_publish.sh
bcd0740fa72c:~ sobkamil$ touch /tmp/publish-results
bcd0740fa72c:~ sobkamil$ ./test_publish.sh
Success! Lerna publish succeeded.
bcd0740fa72c:~ sobkamil$ cp ./lerna_error.txt /tmp/publish-results
bcd0740fa72c:~ sobkamil$ ./test_publish.sh
Fail! Lerna error.
bcd0740fa72c:~ sobkamil$ echo $?
1
bcd0740fa72c:~ sobkamil$ cat test_publish.sh
  number_of_lerna_errors=$(grep -c "lerna ERR" /tmp/publish-results)
  if [[ number_of_lerna_errors -gt 0 ]]; then
    echo "Fail! Lerna error."
    exit 1;
  else
    echo "Success! Lerna publish succeeded."
  fi
bcd0740fa72c:~ sobkamil$ cate lerna_error.txt
-bash: cate: command not found
bcd0740fa72c:~ sobkamil$ cat lerna_error.txt
lerna notice 8.9MB   resources/codepipeline-action-buildspec-generator-lambda.zip
lerna notice 21.0kB  resources/custom-resource-pipeline-awaiter.zip
lerna notice === Tarball Details ===
lerna notice name:          @aws-amplify/amplify-provider-awscloudformation
lerna notice version:       8.6.0-rc.0d5077acf100296.0
lerna notice filename:      aws-amplify-amplify-provider-awscloudformation-8.6.0-rc.0d5077acf100296.0.tgz
lerna notice package size:  8.8 MB
lerna notice unpacked size: 10.6 MB
lerna notice shasum:        fd256b3546ae6e39d682aa6e27902471051e46ea
lerna notice integrity:     sha512-w5/Dc8HrHkFph[...]1ktaPhRdY4fUw==
lerna notice total files:   541
lerna notice
lerna ERR! E503 Service Unavailable
bcd0740fa72c:~ sobkamil$

After changing grep -c to grep .. | wc -l

bcd0740fa72c:~ sobkamil$ nano test_publish.sh
bcd0740fa72c:~ sobkamil$ rm /tmp/publish-results
bcd0740fa72c:~ sobkamil$ touch /tmp/publish-results
bcd0740fa72c:~ sobkamil$ ./test_publish.sh
Success! Lerna publish succeeded.
bcd0740fa72c:~ sobkamil$ echo $?
0
bcd0740fa72c:~ sobkamil$ cp lerna_error.txt /tmp/publish-results
bcd0740fa72c:~ sobkamil$ ./test_publish.sh
Fail! Lerna error.
bcd0740fa72c:~ sobkamil$ echo $?
1

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Pull request labels are added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.