Use tasty for tests, fix bug in circOnLine

src/Geometry/LHS.hs

@@ -3,7 +3,7 @@ module Geometry.LHS
     , isRHS
     ) where
 import Geometry.Data
--- | Test whether a point is on the LHS of a line.
+-- | Test whether a point is stricly on the LHS of a line.
 -- Returns False if the line is of zero length.
 isLHS 
     :: Point2  -- ^ First line point.