Only build for JDK8 (#214)

Author: mdedetrich

.github/workflows/ci.yml

@@ -22,8 +22,8 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.12.14]
-        java: [temurin@8, temurin@11, temurin@17]
+        scala: [2.12.15]
+        java: [temurin@8]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout current branch (full)
@@ -38,20 +38,6 @@ jobs:
           distribution: temurin
           java-version: 8
 
-      - name: Setup Java (temurin@11)
-        if: matrix.java == 'temurin@11'
-        uses: actions/setup-java@v2
-        with:
-          distribution: temurin
-          java-version: 11
-
-      - name: Setup Java (temurin@17)
-        if: matrix.java == 'temurin@17'
-        uses: actions/setup-java@v2
-        with:
-          distribution: temurin
-          java-version: 17
-
       - name: Cache sbt
         uses: actions/cache@v2
         with:

build.sbt

@@ -1,6 +1,6 @@
 import scala.collection.JavaConverters._
 
-scalaVersion := "2.12.15"
+ThisBuild / scalaVersion := "2.12.15"
 
 sbtPlugin        := true
 crossSbtVersions := List("1.0.0")
@@ -43,9 +43,7 @@ packageSrc / publishArtifact := false
 ThisBuild / githubWorkflowPublishTargetBranches := Seq()
 
 ThisBuild / githubWorkflowJavaVersions := List(
-  JavaSpec.temurin("8"),
-  JavaSpec.temurin("11"),
-  JavaSpec.temurin("17")
+  JavaSpec.temurin("8")
 )
 
 ThisBuild / githubWorkflowTargetBranches := Seq("master")