PHPLIB-132: Add MongoDB 3.2 to Travis CI build matrix
PHPLIB-132: Add MongoDB 3.2 to Travis CI build matrix

Fiskie/mongo-php-library,derickr/mongo-php-library-prototype,mongodb-labs/mongo-php-library-prototype,mongodb/mongo-php-library,jmikola/mongo-php-library,derickr/mongo-php-library,jmikola/mongo-php-library,jmikola/mongo-php-library-prototype,jmikola/mongo-php-library,jmikola/mongo-php-library,mongodb/mongo-php-library,mongodb/mongo-php-library,derickr/mongo-php-library,mongodb/mongo-php-library,10gen-labs/mongo-php-library-prototype