Changes

• Auto-discovery of project-id on Google Compute Engine
• Support getting project id from GCE auth compute
• New dataset access DSL for BigQuery
• New table schema DSL for BigQuery
• Add Code of Conduct

Minor changes

• Load data to BigQuery from Datastore backup
• Add Job#wait_until_complete convenience method to BigQuery
• Add String representation of tables in BigQuery
• Add refresh! methods to Storage and BigQuery
• Support DATASTORE_DATASET environment variable
• Update Storage and BigQuery documentation for possible errors during large file uploads
• Fix missing Pathname require
• Truncate object representation in interactive output