Integrate Application Insights

[felixnext]

Integrated new decorators for creating clean functions and passing through a logger object.
Also implemented OpenCensus Event and Logger items to be passed through to sync items to AppInsights.

Prepares for #9
Closes #6

[felixnext]

Still in draft. Open Tasks:

• Update documentation on decorators
• Properly implement Metrics
• Fully test AppInsights sync in example function
• Test the last_decorator flag
• Provide sample implementations of metrics (call count & function runtime)
• Split out function app examples
• Integrate unit tests for all parts (including loglisthandler)
• Ensure that decorator implementation is correct
• Ensure in-order execution of unit-tests to avoid flakyness (i.e. results from global objects leaking into one another)
• Add Unit Tests for remaining decorators
• Implement proper mocking of Insights Functions (AzureLogExporter and AzureEventExporter) - might use a None Key to avoid passing them along? - pushed to Increase Unit-Test Coverage for Insights Decorators #14
• Fix data retrieval from MetricsHandler and make it multi-thread / multi-metrics safe (unit-test flakyness)
• Add Unit Tests for MetricDecorator
• Look into porting to OpenTelemetrics Port Metrics SDK to OpenTelemetry #16

[felixnext]

Now also address #12 - Also added a bunch of unit tests

[felixnext]

Also closes #9 - Note that this shapes up to be a breaking change - therefore bumped version to next major (1.0.0)