Basic runner script using new run_events function

[joott]

Created script bin/schedule.jl to serve as primary interface with framework to schedule graphs.

• New function run_events, replacing the previous schedule_graph_with_notify to obscure most of the setup
• Removed parse_graphs function since we're interested in scheduling the same graph many times
• Runner script with options for data flow graph, number of events to schedule, and max number of concurrent graphs

[m-fila]

I'll rebase and add logging with LocalEventLog and :graphviz_simple we had in the examples and it can go