0.3.1 release

[Alexkun]

What is the purpose of the change

Related issues: #95, #96, #97, #98, #99, #100, #101, #102, #103, #104, #105, #106, #107, #108, #109, #110, #111, #112, #113, #114

Brief change log

1. Support job-level resource downloading.
2. Supports viewing and downloading of meta.json of existing execution history tasks.
3. Add audit log recording to Streamis.
4. Support batch enable and disable jobs.
5. Adjust the default snapshot root address based on the high availability policy.
6. Add cluster high availability query interface.
7. Add heartbeat for callback log.
8. add hook before flink apps stop.
9. Add token in /upload interface.
10. Add support for args with spaces.
11. Error code optimization to identify failed submission exceptions
12. Adding project-level configuration templates.

Verifying this change

(Please pick either of the following options)
This change is a trivial rework / code cleanup without any test coverage.
(or)
This change is already covered by existing tests, such as (please describe tests).
(or)
This change added tests and can be verified as follows:
(example:)

• Added tests for creating and execute the Streamis jobs and verify the availability of different Streamis Job, such as flinkSQL, Jar.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes / no)
• Anything that affects deployment: (yes / no / don't know)
• The Core framework, i.e., JobManager, Server.: (yes / no)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[Davidhua1996]

LGTM.