Replace ApplicationInsights-Python with opencensus-python

[etrepum]

https://github.com/microsoft/ApplicationInsights-Python has been deprecated in favor of https://github.com/census-instrumentation/opencensus-python

[etrepum]

See also:

• https://github.com/census-instrumentation/opencensus-python/tree/master/contrib/opencensus-ext-logging
• https://github.com/census-instrumentation/opencensus-python/tree/master/contrib/opencensus-ext-flask
• https://github.com/census-instrumentation/opencensus-python/tree/master/contrib/opencensus-ext-azure