Add missing tests

[damien-carcel]

Q	A
Bug report?	no
Feature request?	no
BC Break report?	no
RFC?	no
Affected image and tag	all

Some tests are already added, thanks to a basic test runner in bash. However, some tests performed on akeneo/php are missing on akeneo/fpm and akeneo/apache.

More important, the test runner is not able currently to alter the containers configuration (for example activating xdebug through a variable environment and testing it is active).