Invoke phpcpd as per its command-line help.

[alxp]

What does this Pull Request do?

Fix breaking builds first noticed on this PR: Islandora/islandora_defaults#75

• Related GitHub Issue: (link)

#14 [BUG]phpcpd is being invoked incorrectly

What's new?

Changes how phpcpd is invoked in travis_scripts.sh

• Does this change add any new dependencies? No
• Does this change require any other modifications to be made to the repository
  (i.e. Regeneration activity, etc.)? No
• Could this change impact execution of existing code? No

How should this be tested?

Kick off a build of the above islandora_defaults PR.

Documentation Status

• Does this change existing behaviour that's currently documented? No
• Does this change require new pages or sections of documentation? No
• Who does this need to be documented for? N/A
• Associated documentation pull request(s): ___ or documentation issue ___

Interested parties

Tag (@ mention) interested parties or, if unsure, @Islandora/committers