updating PHP SDK to new API level

- adding bank api
- adding payments api
- adding user api
adding additional php versions to travis

and hope for the best
adding new certificate fingerprint
updating readme
[Travis] 5.2 does not run composer and hvvm has issues connecting

also adding 5.6 to be ready for the future
updating readme to changed API
fix bad handling when passing in an invalid code/token
adding demo apps
incrementing version
Adding missing bank_id to bank
Fix demo references
Merge pull request #4 from piotrowski/patch-1

Fix demo references
Merge branch 'master' of https://github.com/figo-connect/php-figo