- Build receivers and plug them into pipelines.

- Added tests to verify that single pipeline and multiple pipeline (fan out)
  per receiver work correctly.

- Disable -v flag in go test to reduce unnecessary noise in output, we have
  too many tests to use -v flag. Errors are still properly printed. This makes
  finding the cause of test failures easier.

- Add logging to various application startup steps.

- Changed logging from %q to %s in multiple places to make it more human readable
  when output in json format.

Testing done:

1. make && all unit tests pass.

2. make otelsvc and produce otelsvc_linux executable.

3. Manually verify that otelsvc_linux runs and correctly forwards trace data
   received via jaeger receiver and exported via opencensus exporter.

   This is the first successful run of unified OpenTelemetry Service.