Updated Scallop library to 4.0.1

Author: mschwerhoff

build.sbt

@@ -47,7 +47,7 @@ lazy val silver = (project in file("."))
     libraryDependencies += "org.scalatest" %% "scalatest" % "3.1.2",                            // Testing
     libraryDependencies += "org.scala-lang.modules" %% "scala-parser-combinators" % "1.1.2",    // Parsing
     libraryDependencies += "com.lihaoyi" %% "fastparse" % "2.2.2",                              // Parsing
-    libraryDependencies += "org.rogach" %% "scallop" % "3.5.0",                                 // CLI parsing
+    libraryDependencies += "org.rogach" %% "scallop" % "4.0.1",                                 // CLI parsing
     libraryDependencies += "commons-io" % "commons-io" % "2.8.0",                               // I/O
     libraryDependencies += "com.google.guava" % "guava" % "29.0-jre",                           // Collections
     libraryDependencies += "org.jgrapht" % "jgrapht-core" % "1.5.0",                            // Graphs