Collating analysis-ready *count* data

[bsaul]

@IJBG - this is still a WIP, but it's probably worth checking out as we'll probably discuss this PR at tomorrow's meeting.

You can test with:

rm(list = ls())
devtools::load_all()
logger::log_threshold(logger::TRACE)

x <- create_mbbs()
x$stop_level
x$route_level

The create_mbbs does not deal with observers, habitat, comments, vehicles, etc. I think we want to deal that stuff separately, since that information is about a route and not a stop. This function is purely meant to create a dataset of counts both at the stop and route level.

[bsaul]

@IJBG - I'll call this ready for review -- it's an initial pass at collating count data.