Fixed 'no point in poly' error

pointdexter 0.1.1

• Added 2010 Chicago census tracts as built-in data sets as both sf and SpatialPolygonDataFrame objects
• Fixed an error where LabelPointsWithinPolygons() failed when no point(s) lay within a polygon.
  • By using smaller geographies (i.e. census tracts) rather than larger ones (i.e. community areas), pointdexter's 0.1.0 method of labeling did not account for instances where a polygon has no points laying inside of it.
  • Resolved by storing the results of splancs::inpip() for each polygon as a named integer vector in a list rather than in a data frame.