PHP version

[kitsook]

There is a discrepancy on PHP version used in different environment:

• docker dev: 5.6
• Travis tests: 5.4, 5.5, 5.6
• Production / verf: 5.3

Need to align the environment either by upgrading the production or adding 5.3 to Travis

[kitsook]

There was a change to remove PHP 5.3 from Travis

https://github.com/ubc/iPeer/commit/589ebf753832a10ce989031c404bf6ae38820b8b

[xcompass]

It is because travis doesn't support 5.3 anymore. I'm planning to run containers in production. We should be able to remove 5.3 support completely once we switch.