Move WebGoat to Java 15

.github/workflows/build.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        java: [11, 15]
+        java: [15]
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK ${{ matrix.java }}

.github/workflows/release.yml

@@ -16,10 +16,10 @@ jobs:
         id: tag
         uses: dawidd6/action-get-tag@v1
 
-      - name: Set up JDK 11
+      - name: Set up JDK 15
         uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 15
           architecture: x64
 
       - name: Cache Maven packages
@@ -111,10 +111,10 @@ jobs:
           ref: develop
           token: ${{ secrets.WEBGOAT_DEPLOYER_TOKEN }}
 
-      - name: Set up JDK 11
+      - name: Set up JDK 15
         uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 15
           architecture: x64
 
       - name: Set version to next snapshot