[EPIC] Fix any bugs that might be found while during a run through of the script

[edwinkortman]

This spawns from #274

List of issues found during testing:

• git is missing from production Docker container image #342
• Fix url for viewing results #343
• Fix serialization error when retrieving release history for pkg:maven/javax.inject/javax.inject dependency-history-maven#26
• Retry with backoff when making HTTP requests against a repository dependency-history-maven#27
• Fix serialization exception when getting history for pkg:maven/aopalliance/aopalliance dependency-history-maven#34
• Handle "database is locked" error when writing to cache database #346
• Handle child modules in multi-module project #347
• Retry on connection reset exception dependency-history-maven#35
• Retry connection when ConnectException is thrown dependency-history-maven#38
• Prevent process-manifests from being called in parallel for the same directory #361

[mscottford]

I've removed #371 from this list because the underlying issue (corgibytes/dependency-history-maven#40) has been fixed, and this problem is no longer blocking a demo.