Compatibility with curb 1.0.0

[peret]

Hello,

we are using curb 1.0.0 and webmock 3.14.0 and are getting the following warning when running tests:
"You are using Curb 1.0.0. WebMock is known to work with Curb >= 0.7.16, < 0.10, except versions 0.8.7. It may not work with this version"

I did not notice any issues so far, though. What would be required to establish compatibility with curb 1.0.0 and update the supported version range?

[pboling]

This may be related #968