Unhandled option values throws exception

[jimk-bdrc]

Describe the bug Audit tool throws an unhandled exception when an unknown flag is given.

To Reproduce Launch audit-tool with the --help flag:

$ audit-tool --help

You will see a warning about an unknown flag, the standard usage output (as if audit-tool was given with no arguments), but then you'll see an unhandled exception (see Screenshots below)

Expected behavior Don't display the unhandled exception, exit with return code 0

Screenshots This shows the existing behavior

ERROR Failed to parse Unrecognized option: --help
usage: audit-tool [options] { - | Directory,Directory,Directory}
where:

                  - read folders from standard input

                  Directory .... is a list of directories separated by
                  whitespace
[options] are:
 -d,--debug             Show debugging information
 -i,--inputFile <arg>   Input file, one path per line
 -l,--log_home <arg>    Test Result log directory. Must be writable.
                        Default is <UserHome>/audit-test-logs/. Created if
                        not exists
Exiting on exception Cannot invoke "org.apache.commons.cli.CommandLine.hasOption(String)" because "this.cl" is null
ERROR java.lang.NullPointer

[jimk-bdrc]

Merged in PR #155