Unimplemented features

[maxcmiller]

• Formatting of dependencies into YAML list
• Ability to choose ChalkBox version to use for JavaEngine in web UI
• Allow selection of assessable test classes from uploaded files in solution
• Fix path names of assessable test classes when generating YAML (directory names -> package names)
• Allow selection of Checkstyle excluded paths
• Intelligent generation of the expected structure directory based on solution and assessable test classes
• Have Checkstyle .jar be separately uploaded in its own drop zone and renamed to something standard