Using pipeline-live with pylivetrader

In this release, we strengthen the integration between the two packages: pylivetrater and pipeline-live to work together to have daily screening capabilities.

• you can now use attach_pipeline and pipeline_output to use pipeline live inside pylivetrader
• created new example code to get the user started:
  • simple MACD example (updated)
  • simple pipeline-live usage example
• added smoke scripts to example algos. check the READMEs
• added argument for pipeline output hook to Algorithm()
• udpated the minimum Alpaca SDK to 0.46

Fixes

• don't pickle your pipeline when storing the state file
• fix the smoke tool to work with mocked pipeline output
• small fixes to smoke backend to be able to work with pipeline-live mock
• we change the yaml config loading to use the safe loading (security fix)