Added --version flags to trace and boostrap commands

[owais]

The --version flag makes the command print version information that
looks like the following:

splunk-opentelemetry==0.1.8

Also uses the following OpenTelemetry libraries:

	opentelemetry-api==0.*,>=0.14.0.b0
	opentelemetry-exporter-zipkin==0.*,>=0.14.0.b0
	opentelemetry-instrumentation==0.*,>=0.14.0.b0
	opentelemetry-sdk==0.*,>=0.14.0.b0

Also replaces splunk.distro.version resource attribute with telemetry.auto.version.