use install in 1st build

Author: stefanseifert

.github/workflows/maven-build.yml

@@ -42,9 +42,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-maven-
 
-      # Build & verify
+      # Build & install (required for 2nd build: example)
       - name: Build and verify
-        run: mvn -s ./.maven-settings.xml -Pcontinuous-integration -B -U clean verify
+        run: mvn -s ./.maven-settings.xml -Pcontinuous-integration -B -U clean install
 
       # Build & verify example
       - name: Build and verify example