feat : config airflow BaseOperator

[irainia]

This PR is to address issue mentioned here #263 .

Changes

• add Airflow under metadata to allow the user to put config related to pool and queue.

Example

...
dependencies: []
hooks: []
metadata:
  ...
  airflow:
    pool: poolA
    queue: queueA

Fix

• fix error message when encountered deployment failure

Note

In order for this PR to be merged, the following has to be done:

• merge PR in Proton required by this PR

[coveralls]

Pull Request Test Coverage Report for Build 2182658283

• 24 of 36 (66.67%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 75.112%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
store/local/job_spec_adapter.go	10	14	71.43%
api/handler/v1beta1/adapter.go	10	18	55.56%

Totals
Change from base Build 2165523692:	-0.05%
Covered Lines:	6027
Relevant Lines:	8024

---

💛 - Coveralls

[irainia]

@sravankorumilli , I've tested this in my local, and so far no issue is found and the configuration is passed and used. Please check this if there's any concern or issue.

[sravankorumilli]

fixes #263