bump Scala and sbt versions

the sbt version bump is crucial because 1.2.8 doesn't work
on JDK 13

Author: SethTisue

README.md

@@ -2,7 +2,7 @@ A [Giter8][g8] template for a Hello World application, used in the [Getting Star
 
 Template license
 ----------------
-Written in 2017-2018 by the Scala Center
+Written in 2017-2019 by the Scala Center
 
 To the extent possible under law, the author(s) have dedicated all copyright and related
 and neighboring rights to this template to the public domain worldwide.

src/main/g8/build.sbt

@@ -1,15 +1,15 @@
 
 // The simplest possible sbt build file is just one line:
 
-scalaVersion := "2.12.8"
+scalaVersion := "2.13.1"
 // That is, to create a valid sbt build, all you've got to do is define the
 // version of Scala you'd like your project to use.
 
 // ============================================================================
 
 // Lines like the above defining `scalaVersion` are called "settings" Settings
 // are key/value pairs. In the case of `scalaVersion`, the key is "scalaVersion"
-// and the value is "2.12.8"
+// and the value is "2.13.1"
 
 // It's possible to define many kinds of settings, such as:
 
@@ -24,7 +24,7 @@ version := "1.0"
 
 // Want to use a published library in your project?
 // You can define other libraries as dependencies in your build like this:
-libraryDependencies += "org.typelevel" %% "cats-core" % "1.6.0"
+libraryDependencies += "org.typelevel" %% "cats-core" % "2.0.0"
 // Here, `libraryDependencies` is a set of dependencies, and by using `+=`,
 // we're adding the cats dependency to the set of dependencies that sbt will go
 // and fetch when it starts up.
@@ -34,7 +34,7 @@ libraryDependencies += "org.typelevel" %% "cats-core" % "1.6.0"
 // TIP: To find the "dependency" that you need to add to the
 // `libraryDependencies` set, which in the above example looks like this:
 
-// "org.typelevel" %% "cats-core" % "1.6.0"
+// "org.typelevel" %% "cats-core" % "2.0.0"
 
 // You can use Scaladex, an index of all known published Scala libraries. There,
 // after you find the library you want, you can just copy/paste the dependency
@@ -66,7 +66,7 @@ libraryDependencies += "org.typelevel" %% "cats-core" % "1.6.0"
 //   settings(
 //     inThisBuild(List(
 //       organization := "ch.epfl.scala",
-//       scalaVersion := "2.12.8"
+//       scalaVersion := "2.13.1"
 //     )),
 //     name := "hello-world"
 //   )

src/main/g8/project/build.properties

@@ -1 +1 @@
-sbt.version=1.2.8
+sbt.version=1.3.2