Update dependency com.google.apis:google-api-services-discovery to v1-rev20190129-1.30.8
Update dependency com.google.apis:google-api-services-discovery to v1-rev20190129-1.30.8

GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples