Make progress bar at most 50 characters wide.

[coollog]

Make progress bar and task descriptions at most 50 characters wide.

This helps avoid output messing up like:

[INFO] --- jib-maven-plugin:0.10.2-SNAPSHOT:build (default-cli) @ spring-petclinic ---
[INFO] 
[INFO] Containerizing application to gcr.io/tcordle-test/petclinic...
[WARNING] Base image 'gcr.io/distroless/java' does not use a specific image digest - build may not be reproducible
[INFO] Executing tasks:
[INFO] Executing tasks:
[INFO] Executing tasks:
[INFO] [=============                                     ] 25.5% complete
[INFO] > building dependencies layer
[INFO] Executing tasks:
[INFO] [=============                                     ] 25.5% complete
[INFO] > building dependencies layer
[INFO] Executing tasks:
[INFO] [=============                                     ] 25.5% complete
[INFO] Executing tasks:
[INFO] [=============                                     ] 27.0% complete
[INFO] Executing tasks:
[INFO] 
[INFO] Container entrypoint set to [java, -cp, /app/resources:/app/classes:/app/libs/*, org.springframework.samples.petclinic.PetClinicApplication]
[INFO] 
[INFO] Built and pushed image as gcr.io/tcordle-test/petclinic
[INFO] Executing tasks:
[INFO] [==================================================] 100.0% complete
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 27.307 s
[INFO] Finished at: 2018-12-18T11:48:38-05:00
[INFO] Final Memory: 93M/1019M
[INFO] ------------------------------------------------------------------------