NIFI-3650 - Adjust travis to forcefuly remove $HOME/.m2/repository/or…

[trixpan]

…g/apache/nifi/

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[trixpan]

@apiri @jfrazee - hopefully this will work.

[apiri]

@trixpan Do you think it makes more sense to use the before_cache directive instead? (https://docs.travis-ci.com/user/caching/#before_cache-phase) May just be struggling in the morning, but I believe this is likely the preferred approach.

[jfrazee]

@apiri I think there might be two tasks here to make sure everything is copacetic: (1) remove that part of the tree so we don't bother caching it/downloading it period and (2) removing it before the build just to make sure it's not there (will need that the first time this runs anyway if we don't invalidate the cache).

So I think it makes sense to add this but also keep the other.

[jfrazee]

@apiri Oh, I see now. You're saying move the one in script to before_cache.

[trixpan]

@apiri good catch. I wasn't aware of that feature. I pushed a modified version. let me know what you think

[trixpan]

I am obviously happy to remove the pre-build cache "rm -rf" but since it should not return error, so I reckon we can leave it there as a safety mechanism in case before_cache fails

[apiri]

@trixpan don't think removing it is necessary by any means. I also find it hard to say exactly how all these Travis options play out, but I think this is a step in the right direction. Scientific Method at its finest! Anyway, changes look good and I shall merge it.