I wanted to install `amqp` with pecl for my mac sierra. 

I installed php with brew, with `pecl install amqp` I receive an error: `checking for amqp using pkg-config... configure: error: librabbitmq not found`

I installed with brew the `librabbitmq-c` package but I still get this error. I think it's somehow not synced with the pkg-config. 

Does someone have an idea what to do here?