Bump swoval to v2.1.12

For somewhat unknown reasons the native directory lister was very slow
on windows for repos with deeply nested directory trees. This new
version of swoval defaults to nio apis for Windows while retaining the
native listers on posix platforms (where as far as I know there are no
performance issues).

See swoval/swoval#161.

project/Dependencies.scala

@@ -16,5 +16,5 @@ object Dependencies {
   val jnaVersion = "5.13.0"
   val jna = "net.java.dev.jna" % "jna" % jnaVersion
   val jnaPlatform = "net.java.dev.jna" % "jna-platform" % jnaVersion
-  val swovalFiles = "com.swoval" % "file-tree-views" % "2.1.10"
+  val swovalFiles = "com.swoval" % "file-tree-views" % "2.1.12"
 }