ci: Run source clear before linting and tests.

[oakbani]

Summary

Stages run sequentially on Travis. If a stage fails, all the following stages are not executed. We execute source clear only on cron, and if due to any reason unit or integration tests fail, the source clear is not executed. Hence, moving source clear stage before tests.

Test plan

All unit tests must be passed.
FSC must be passed.

[coveralls]

Pull Request Test Coverage Report for Build 1471

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 89.419%

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Totals
Change from base Build 1469:	0.0%
Covered Lines:	3955
Relevant Lines:	4423

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 1471

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 89.419%

---

Totals
Change from base Build 1469:	0.0%
Covered Lines:	3955
Relevant Lines:	4423

---

💛 - Coveralls

[msohailhussain]

lgtm