Enable Ollama integration test

Currently, test is disable because in every run the image should
be downloaded and then pull the model. Now, taking advantage of
Testcontainers and a GHA, a new image is created on-the-fly with
the model in it and then cached, so, next executions will reuse the
cached image instead.

Fixes #121

.github/workflows/continuous-integration.yml

@@ -19,6 +19,11 @@ jobs:
           distribution: 'temurin'
           cache: 'maven'
 
+      - name: Cache Docker images.
+        uses: ScribeMD/docker-cache@0.3.6
+        with:
+          key: docker-${{ runner.os }}-${{ hashFiles('**/OllamaImage.java') }}
+
       - name: Build with Maven and deploy to Artifactory
         env:
           OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}