Changed RV angle parameter to strenght parameter.

Rules.jl

@@ -44,9 +44,9 @@ module Rules
         set!(turtle, to = pos(turtle), head = Vec(NewHead), up = Vec(NewUp), arm = Vec(NewArm))
     end
     struct RV{FT} <: VPL.Node 
-        angle::FT
+        strength::FT
     end
-    VPL.feedgeom!(turtle::MTurtle, node::RV) = rv!(turtle, node.angle)
+    VPL.feedgeom!(turtle::MTurtle, node::RV) = rv!(turtle, node.strength)
 
     # Define rule for phytomer production
     function producePhytomer(M)