Update pora Dockerfile to actually compile pora

[ameowlia]

Are you submitting this PR against the develop branch?

Yes

What is this change about?

We want to update the Dockerfile to actually work :)

Please provide contextual information.

ARP WG is taking over volume services and revamping a few things, including this.

What version of cf-deployment have you run this cf-acceptance-test change against?

CATs does not use this dockerfile

Please check all that apply for this PR:

• introduces a new test --- Are you sure everyone should be running this test?
• changes an existing test
• requires an update to a CATs integration-config

Did you update the README as appropriate for this change?

• YES
• N/A

If you are introducing a new acceptance test, what is your rationale for including it CATs rather than your own acceptance test suite?

We want to keep pora where it is.

How many more (or fewer) seconds of runtime will this change introduce to CATs?

0!

What is the level of urgency for publishing this change?

• Urgent - unblocks current or future work
• Slightly Less than Urgent

Tag your pair, your PM, and/or team!

@winkingturtlevmw