Travis-CI: Don'T use latest paramiko
Travis-CI: Don'T use latest paramiko

Exscript doesn't work with paramiko>=1.15.0.
At least the tests: "error: Socket is closed"
See https://github.com/knipknap/exscript/issues/79

maximumG/exscript,knipknap/exscript,knipknap/exscript,maximumG/exscript