Update scalatest to 3.2.18 (#1161)

build.sbt

@@ -8,7 +8,7 @@ val javaEwahVersion = "1.2.3"
 val kindProjectorVersion = "0.13.2"
 val paradiseVersion = "2.1.1"
 val quasiquotesVersion = "2.1.0"
-val scalaTestVersion = "3.2.17"
+val scalaTestVersion = "3.2.18"
 val scalaTestPlusVersion = "3.1.0.0-RC2"
 val scalacheckVersion = "1.15.2"
 val scalaCollectionCompat = "2.11.0"