Assume dictionary keys are non-null
Merge pull request #278 from sharwell/NonNullKeys

Assume dictionary keys are non-null
checkpoint
Support and testing for agent connections
Updated monitoring cleanup test methods
Support and testing for agent tokens
Many updates
More updates
Fix a bunch of build warnings
Simplify DateTimeOffset <-> timestamp conversions with new utility class
Implement many more monitoring methods
Implement remaining monitoring methods
Create specialized NotificationDetails classes for each predefined notification type
Fix method names
Support the created_at, updated_at, and metadata properties for notifications
Updated implementation and tests for notifications and notification plans
Updated notifications tests
Updated traceroute support and tests
Updated integration test logging
Updated monitoring zone tests