Customizable timeout

[cqcwillard]

If you are using the library in a vagrant environment with a localized hostname, the 5 second timeout is not enough for the ExecTransport to successfully send the curl payload.

Having the timeout set in the Api class as a constant prevents users from being able to change this option. Could this please be modified to use the options array in the ExecTransport constructor?

[cqcwillard]

This was a reverse-dns lookup issue with curl, the problem is not with the api.