Per @dhermes and @tseaver's conversation.

Services with tested snippets

• Add validation script to check for untested snippets.
• Start running snippets during system tests.
• Bigquery (docs/bigquery_snippets.py) (partial)
• Bigtable
• Datastore
• DNS
• Error Reporting
• Language
• Logging
• Montoring
• Pubsub (docs/pubsub_snippets.py)
• Resource manager
• Speech
• Storage
• Translate
• Vision