Cache path change

[liyongkang123]

Thanks a lot for your great work!!!

Can I change the cache path of Anserini to another path that I want?

In fact, I have set the cache for downloading and code running for Pyserini, but I did not find a way to set the cache path for Anserini.

For example, I run the following code and I will get the output: （code come from ）

python -m pyserini.eval.msmarco_passage_eval msmarco-passage-dev-subset run.msmarco-passage.txt

Downloading https://raw.githubusercontent.com/castorini/anserini-tools/master/scripts/msmarco/msmarco_passage_eval.py to /XXXXXX/cache/eval/msmarco_passage_eval.py...
/XXXXXX/cache/eval/msmarco_passage_eval.py already exists!
Skipping download.
Downloading qrels from https://raw.githubusercontent.com/castorini/anserini-tools/master/topics-and-qrels/qrels.msmarco-passage.dev-subset.txt
Running command: ['python', '/XXXXXX/cache/eval/msmarco_passage_eval.py', '/home/myname/.cache/anserini/topics-and-qrels/qrels.msmarco-passage.dev-subset.txt', 'run.msmarco-passage.txt']

And I found qrels from Anserini was downloaded to the default /home/ myname/.cache folder, not the Pyserini cache folder I set.