Update travis scala version to 2.13.1

Author: rozza

.travis.yml

@@ -4,7 +4,7 @@ language: scala
 scala:
   - 2.11.12
   - 2.12.8
-  - 2.13.0
+  - 2.13.1
 
 jdk:
   - oraclejdk8

project/plugins.sbt

@@ -7,7 +7,7 @@ addSbtPlugin("org.scalariform" % "sbt-scalariform" % "1.6.0")
 
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.6.1")
 
-libraryDependencies += "org.scoverage" %% "scalac-scoverage-runtime" % "1.4.0"
+libraryDependencies += "org.scoverage" %% "scalac-scoverage-runtime" % "1.4.1"
 
 addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.0.0")