Revert "fix nothing to fill in"

This reverts commit fd4b73e.

src/main/scala/monocle/IsoExercises.scala

@@ -154,6 +154,7 @@ object IsoExercises extends FlatSpec with Matchers with Section {
     *     i.get(i.reverseGet(a)) == a
     * }}}
     */
+  def conclusion(): Unit = ()
 
 
 }

src/main/scala/monocle/LensExercises.scala

@@ -156,5 +156,6 @@ object LensExercises extends FlatSpec with Matchers with Section {
       *     l.get(l.set(a)(s)) == a
       * }}}
       */
+    def conclusion(): Unit = ()
 
 }

src/main/scala/monocle/OptionalExercises.scala

@@ -128,6 +128,7 @@ object OptionalExercises extends FlatSpec with Matchers with Section {
     *
     * `setGetOption` states that if you `set` a value, you always `getOption` the same value back.
     */
+  def conclusion(): Unit = ()
 
 
 }

src/main/scala/monocle/PrismExercises.scala

@@ -188,6 +188,7 @@ object PrismExercises extends FlatSpec with Matchers with Section {
     *     p.getOption(p.reverseGet(a)) == Some(a)
     * }}}
     */
+  def conclusion(): Unit = ()
 
 
 }

src/main/scala/monocle/TraversalExercises.scala

@@ -145,6 +145,7 @@ object TraversalExercises extends FlatSpec with Matchers with Section {
     *     t.modify(g)(t.modify(f)(s)) == t.modify(g compose f)(s)
     * }}}
     */
+  def conclusion(): Unit = ()
 
 
 }