Fix "Log4j API could not find a logging provider"

[bact]

When running mvn verify, got this error message:

main ERROR Log4j API could not find a logging provider.

Apache POI (used by the spreadsheet store) uses log4j-api.
Our project uses slf4j-simple provider, so add log4j-to-slf4j as adapter, to fix the error.

[goneall]

I recall a past issue where it was requested that we not specify a specific logging provider. That may have been an issue with a library, however (it was some time ago).

Before merging this in, we should find the previous issue and make sure this change doesn't re-introduce it.

[goneall]

@bact - this is marked as draft, but it looks ready to go - let me know if it's OK to merge

[bact]

@goneall I have mark this are ready again so you can merge it.
Was marked it as draft because of the earlier comment:

I recall a past issue where it was requested that we not specify a specific logging provider. That may have been an issue with a library, however (it was some time ago).

Before merging this in, we should find the previous issue and make sure this change doesn't re-introduce it.

Relevant logging comment may be this one from @pmonks ?

#153 (comment)

[goneall]

@bact - In reviewing the related issues / PR's, I'm reasonably confident this won't re-introduce the errors - so I'll go ahead and merge.

@vargenau @pmonks - Just a heads up that there is a small possibility this may re-introduce a previous issue #153

[pmonks]

My understanding is that tools-java is an application, rather than a library, in which case it should include a logging implementation in the classpath.

The general rule about not providing logging implementations (so as to allow downstream consumers to use whichever implementation they wish) only applies to libraries.