Added test to validate #10.

Author: darkfrog26

shared/src/test/scala/specs/DepsSpec.scala

@@ -207,6 +207,13 @@ class DepsSpec extends WordSpec with Matchers {
         right() should be(550.0)
         leftValue should be(450.0)
       }
+      "increment center from itself" in {
+        center := center() + 10.0
+        center() should be(510.0)
+        left() should be(460.0)
+        right() should be(560.0)
+        leftValue should be(460.0)
+      }
     }
   }
 }