Drop sbt 0.13.x support

Author: Alex Zolotko

README.md

@@ -17,7 +17,7 @@ Add following to `project/plugins.sbt`
 ```
 resolvers += "TNM" at "https://nexus.thenewmotion.com/content/groups/public"
 
-addSbtPlugin("com.newmotion" % "sbt-build-seed" % "5.0.7")
+addSbtPlugin("com.newmotion" % "sbt-build-seed" % "5.1.0")
 ```
 
 To develop a library in your build.sbt use:
@@ -44,6 +44,10 @@ If you keep updating sbt-extras you'll always have up-to-date sbt at your dispos
 
 ### Requirements ###
 
+Releases `>= 5.1.0`
+- Java 8
+- sbt `>= 1.3.0`
+
 Releases `>= 2.0.1`
 - Java 8
 - sbt `>= 0.13.13`

build.sbt

@@ -6,7 +6,6 @@ enablePlugins(OssLibPlugin)
 organization := "com.newmotion"
 name := "sbt-build-seed"
 
-crossSbtVersions := Vector("0.13.18", "1.3.13")
 releaseCrossBuild := false
 
 scalaVersion := tnm.ScalaVersion.prev

version.sbt

@@ -1 +1 @@
-version in ThisBuild := "5.0.7-SNAPSHOT"
+version in ThisBuild := "5.1.0-SNAPSHOT"