Update test and add check file

Author: odersky

tests/run/planets.check

@@ -0,0 +1,8 @@
+Your weight on MERCURY is 37.775761520093525
+Your weight on SATURN is 106.60155388115666
+Your weight on VENUS is 90.49990998410455
+Your weight on URANUS is 90.51271993894251
+Your weight on EARTH is 100.0
+Your weight on NEPTUNE is 113.83280724696579
+Your weight on MARS is 37.873718403712886
+Your weight on JUPITER is 253.05575254957407

tests/run/planets.scala

@@ -18,7 +18,7 @@ object Test {
     import Planet._
     assert(enumValueNamed("SATURN") == SATURN)
     assert(enumValue(2) == EARTH)
-    val earthWeight = args(0).toDouble
+    val earthWeight = 100
     val mass = earthWeight/EARTH.surfaceGravity
     for (p <- enumValues)
       println(s"Your weight on $p is ${p.surfaceWeight(mass)}")