opencensus 0.10.0

• Add kwargs to derived gauge
  (#1135)

opencensus-ext-azure 1.1.5

• Allow specifying metrics (custom_measurements) for Azure custom events
  (#1117)
• Shutdown Statsbeat when hitting error/exception threshold
  (#1127)
• Fix failure counting statsbeat - refactor status code logic in transport
  (#1132)
• Use logging handler close instead of custom atexit hook
  (#1134)