Update SpaceAge.swift (#871)

Author: meatball133

exercises/practice/space-age/Sources/SpaceAge/SpaceAge.swift

@@ -1,16 +1,3 @@
 class SpaceAge {
-  var seconds: Float = 0
-
-  var onMercury: Float { return ((seconds / 7_600_530.24) * 100).rounded() / 100 }
-  var onVenus: Float { return ((seconds / 19_413_907.2) * 100).rounded() / 100 }
-  var onEarth: Float { return ((seconds / 31_558_149.76) * 100).rounded() / 100 }
-  var onMars: Float { return ((seconds / 59_354_294.4) * 100).rounded() / 100 }
-  var onJupiter: Float { return ((seconds / 374_335_776.0) * 100).rounded() / 100 }
-  var onSaturn: Float { return ((seconds / 929_596_608.0) * 100).rounded() / 100 }
-  var onUranus: Float { return ((seconds / 2_661_041_808.0) * 100).rounded() / 100 }
-  var onNeptune: Float { return ((seconds / 5_200_418_592.0) * 100).rounded() / 100 }
-
-  init(_ input: Float) {
-    self.seconds = input
-  }
+  // Write your code for the 'SpaceAge' exercise in this file.
 }