changed .travis.yml to use preinstalled mongodb extension
changed .travis.yml to use preinstalled mongodb extension

doctrine/DoctrineMongoODMModule,doctrine/DoctrineMongoODMModule,Bilge/DoctrineMongoODMModule,Bilge/DoctrineMongoODMModule,prolic/DoctrineMongoODMModule,doctrine/DoctrineMongoODMModule,prolic/DoctrineMongoODMModule