Support location in bq operator

[tkawachi]

Set Job location for non-US location.

Fixes #1088

[tkawachi]

@yoyama can you review this PR?

[yoyama]

@tkawachi Thank you for your contribution.
I left comments, please check them.
In addition, adding integration tests is preferred.
https://github.com/treasure-data/digdag/blob/master/digdag-tests/src/test/java/acceptance/td/BigQueryIT.java
And we need to update the document as following.
https://docs.digdag.io/operators/bq.html

[tkawachi]

Thank you for your review, @yoyama.
I have added the integration test, but for the extract and load tests, the location of the BigQuery and GCS bucket must match. Currently, I suppose US bucket is set as GCS_TEST_BUCKET, but in addition to this, bucket of other location is needed.
If you can create the bucket for me, I will write an integrated test for extract and load. Since I used asia-northeast1 in other tests, a bucket for asia-northeast1 might be desirable.

[yoyama]

@tkawachi Thank you for your fix.
I created a bucket in asia region and set GCS_TEST_BUCKET_ASIA variable in CircleCI.
Could you confirm it ?

[tkawachi]

@yoyama I wrote tests for load and extract. It assumes that GCS_TEST_BUCKET_ASIA is in asia-northeast1, not asia (BigQuery can't be located in asia). Where can I check the test result of CircleCI?

[yoyama]

@tkawachi I pushed your PR to digdag repo to run CircleCI.
It failed as follows.

https://app.circleci.com/pipelines/github/treasure-data/digdag/718/workflows/237633a7-4be4-4697-8e66-45195f1505b3/jobs/4699/parallel-runs/1?filterBy=ALL

Could you confirm it ?
The root cause is the setting of CircleCI and I fixed and confirmed BigQueryIT* passed.
I faced still a failure but it is not related to this PR.

[yoyama]

@tkawachi I add a minor comment. Could you confirm it ?

[yoyama]

@tkawachi I have an another ask. Could you update the doc on the new parameters ?
The doc on BigQuery is managed in digdag-docs/src/operators/

[tkawachi]

I updated the docs. I didn't change bq_ddl.md since it already mentions about location.

[yoyama]

LGTM.
Thank you for your contribution!

[toru-takahashi]

Hello @tkawachi

Thank you for your great PR and contribution to digdag!
We are really appreciated with your efforts.

We would like to deliver some TD/Digdag swag to you as a token of our appreciation.
If you don't mind, could you fill your address in the following Google form? So that we can send to you.

https://forms.gle/37jhNBFJo9kyLvLx9