Modified usage of cache for CircleCI (#1999)

.circleci/config.yml

@@ -8,21 +8,25 @@ jobs:
 #        user: appuser
     environment:
       _JAVA_OPTIONS: "-Xms1024m -Xmx2048m"
+      CACHEVER: 1
       TERM: dumb
     branches:
       ignore:
         - gh-pages # list of branches to ignore
     steps:
       - checkout
-#      - restore_cache:
-#          key: sc-config-{{ .Branch }}
+      - type: shell
+        name: "Write CACHEVER to file"
+        command: echo "$CACHEVER" > ~/CACHEVER.txt
+      - restore_cache:
+          key: sc-config-{{ .Branch }}-{{ checksum "~/CACHEVER.txt" }}
       - run:
           name: "Download dependencies"
           command: ./mvnw -s .settings.xml -U --fail-never dependency:go-offline || true
-#      - save_cache:
-#          key: sc-config-{{ .Branch }}
-#          paths:
-#            - ~/.m2
+      - save_cache:
+          key: sc-config-{{ .Branch }}-{{ checksum "~/CACHEVER.txt" }}
+          paths:
+            - ~/.m2
       - run:
           name: "Running build"
           command: ./mvnw -s .settings.xml clean org.jacoco:jacoco-maven-plugin:prepare-agent install -U -P sonar,withoutDockerTests -nsu --batch-mode -Dmaven.test.redirectTestOutputToFile=true -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn