run build for all support scala versions

Author: pjfanning

.github/workflows/ci.yml

@@ -26,8 +26,9 @@ jobs:
   build:
     strategy:
       matrix:
-        java: [ '8', '11',  '17' ]
-        os: [ 'ubuntu-latest' ]
+        os: [ubuntu-latest]
+        scala: [2.10.7, 2.11.12, 2.12.15, 2.13.7, 3.0.2]
+        java: ['8', '11',  '17']
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v2
@@ -36,5 +37,16 @@ jobs:
       with:
         java-version: ${{ matrix.java }}
         distribution: 'zulu'
+    - name: Cache sbt
+      uses: actions/cache@v2
+      with:
+        path: |
+          ~/.sbt
+          ~/.ivy2/cache
+          ~/.coursier/cache/v1
+          ~/.cache/coursier/v1
+          ~/AppData/Local/Coursier/Cache/v1
+          ~/Library/Caches/Coursier/v1
+        key: ${{ runner.os }}-sbt-cache-v2-${{ hashFiles('**/*.sbt') }}-${{ hashFiles('project/build.properties') }}
     - name: Build
-      run: sbt -batch "+ test"
+      run: sbt ++${{ matrix.scala }} test

project/Dependencies.scala

@@ -19,7 +19,7 @@ import sbt._
 object Dependencies {
   val scala210 = "2.10.7"
   val scala211 = "2.11.12"
-  val scala212 = "2.12.10"
+  val scala212 = "2.12.15"
   val scala213 = "2.13.7"
   val scala3 = "3.0.2"