Command line app fails because of missing log4j configuration

[ruebot]

Describe the bug Command line app fails because of missing log4j configuration

To Reproduce Steps to reproduce the behavior (e.g.):

1. bin/spark-submit --master local\[8\] ~/Projects/au/aut-releases/aut-0.50.0-fatjar.jar --extractor DomainFrequencyExtractor --input /home/nruest/Projects/au/sample-data/geocities/* --output /home/nruest/Projects/au/sample-data/app-output/DomainFrequencyExtractor

This will produce a misleading message when Spark fires up, then exit without running.

log4j:WARN No appenders could be found for logger (io.archivesunleashed.app.CommandLineApp).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Environment information

• AUT version: 0.50.0
• OS: Ubuntu 18.04
• Java version: Java 8
• Apache Spark version: 2.4.5
• Apache Spark w/aut: submit
• Apache Spark command used to run AUT: `bin/spark-submit --master local\[8\] ~/Projects/au/aut-releases/aut-0.50.0-fatjar.jar --extractor DomainFrequencyExtractor --input /home/nruest/Projects/au/sample-data/geocities/* --output /home/nruest/Projects/au/sample-data/app-output/DomainFrequencyExtractor `

Additional context

One resolution here could be that we ship a sample log4j configuration like this in src/resources, and then document it.

[ruebot]

:man_facepalming: we do ship one https://github.com/archivesunleashed/aut/blob/master/src/main/resources/log4j.properties