Increase test coverage for analyze.go

What does this MR do?

Increased the test-coverage for analyze.go

Before:

➜  spotbugs git:(master) go test -cover
     | [INFO] [2020-09-16T14:55:24-06:00] ▶ Found 0 analyzable projects.
     | [INFO] [2020-09-16T14:55:24-06:00] ▶ Found 0 analyzable projects.
     | PASS
COVER| 19.5% [#_________]
PASS | gitlab.com/gitlab-org/security-products/analyzers/spotbugs/v2 0.165s

After:

➜  spotbugs git:(add_test) go test -cover
     | [INFO] [2020-09-16T16:07:29-06:00] ▶ Found 0 analyzable projects.
     | [INFO] [2020-09-16T16:07:29-06:00] ▶ Found 0 analyzable projects.
     | PASS
COVER| 28.6% [##________]
PASS | gitlab.com/gitlab-org/security-products/analyzers/spotbugs/v2 0.178s

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template (also in CE)
  • Job definition example
  • CI Templates (to be removed)
  • Vendored CI Templates (also in CE)
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer