Upgraded to build pack utils #82089ac.
Upgraded to build pack utils #9e67077
Upgraded build pack utils #1ee7835.
Upgraded version of PHP used by test.
Updated compile script to use the new builder syntax.  This allows for extensions to be registered and then installed separately.  The point of this is to allow the extensions to run prior to being installed and perhaps configure things.  One common use case of this is for extensions to influence the version or extensions enabled by PHP.
Added convenience script to run all tests.
Added __init__.py files.  These are technically required by Python to load an extension.  If an extension doesn't provide this file, it will be automatically added for the build pack.  Thus including it is optional.