Install pylint and coverage if needed.

[nmousavi]

Install pylint and coverage if needed.

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for the commit author(s). If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.
In order to pass this check, please resolve this problem and have the pull request author add another comment and the bot will run again. If the bot doesn't comment, it means it doesn't think anything has changed.

[coveralls]

Pull Request Test Coverage Report for Build 397

• 0 of 0 (NaN%) changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 90.202%

---

Totals
Change from base Build 380:	0.0%
Covered Lines:	3084
Relevant Lines:	3419

---

💛 - Coveralls

[nmousavi]

Run again bot!

[arostamianfar]

Thanks!

[nmousavi]

Closing this since could not figure out the CLA part for this PR. New PR will resolve it.