Attempt to fix CI build.

.github/workflows/gradle.yml

@@ -10,11 +10,15 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 1.8
-      uses: actions/setup-java@v1
+    - uses: actions/checkout@v3
+    - name: Set up JDK 11
+      uses: actions/setup-java@v3
       with:
-        java-version: 1.8
+        distribution: 'temurin'
+        java-version: 11
+
+    - name: Install attr package
+      run: sudo apt-get install -y attr
 
     - name: build and test cadc-util-fs
       run: cd cadc-util-fs && ../gradlew --info clean build javadoc install

cavern/Dockerfile

@@ -1,6 +1,6 @@
 FROM images.opencadc.org/library/cadc-tomcat:1
 
 ## cavern specific
-RUN dnf install -y acl && dnf clean all
+RUN dnf install -y acl attr && dnf clean all
 
 COPY build/libs/cavern.war /usr/share/tomcat/webapps/

cavern/build.gradle

@@ -10,7 +10,7 @@ repositories {
 
 apply from: '../opencadc.gradle'
 
-sourceCompatibility = 1.8
+sourceCompatibility = 11
 
 group = 'org.opencadc'