The fix from PHPLIB-442 also allows this test to pass.

This extracts common logic in next() and rewind() to a new method, which is now also called by resume() after it rewinds the internal iterator.

Support placeholders in DocumentsMatchConstraint and allow CommandExpectations to ignore extra events.

Also removes abstract from base spec test class.

Spec tests synced with mongodb/specifications@a1c9d3c5a7b938f595bb2547c07a238da21263f3

Remove BC test methods for PHPUnit 4.x

b175a3f9 upgraded PHPUnit to 5.7, so these are no longer needed.

Spec tests synced with mongodb/specifications@4820c7bad9b06b71f169c0d4b99aba6fbb319243

PHPLIB-429: Remove support for PHP 5.5

Mark incomplete transaction tests to be fixed before 4.2-compat release.

Changes JSON decoding of spec tests to preserve array/object types.

Bump driver version on Travis CI to include libmongoc 1.14 and PHPC-1373.

Spec tests synced with mongodb/specifications@83a0e6b56bfd73b471c1b740190dbbb7c52ffa92

Additionally, force 14.04 when testing server 3.0.x since it is not available on 16.04

Ensure the command document is non-empty before attempting to access the command and collection names.

Use MultipleIterator::MIT_NEED_ANY to ensure iteration doesn't stop prematurely if one collection contains fewer documents.