Also:
1. Support coverage builds.
2. Add an integration test for coverage builds and reports.
3. Refactor docker code so that there is less duplication in getting arguments for docker run, in particular when handling container (production) vs no container (testing).
4. Rename coverage.py to get_coverage_report.
5. Add tests for untested functions in docker.py
6. Add a test for get_fuzz_target_runner.
Abstract away OSS-Fuzz specific bits into the OSSFuzz implementation
of the ClusterFuzzDeployment class. This will make it easier to implement
support for other deployments of ClusterFuzz (including ClusterFuzzLite).