GetChangesOperation fails on Linux

[ricellis]

Please include the following information in your ticket.

• SwiftCloudant version(s) that are affected by this issue.

0.8.0 (previous versions do not support Linux)

• Swift version(s)

4.0 -> 4.0.3

• Platform(s)

Ubuntu 14.04 (although likely all versions are impacted)

• A small code sample that demonstrates the issue.

See Travis failures for GetChangesTests as referenced in this comment #121 (comment)

As per @ianpartridge in comment #121 (comment) this appears to be a runtime regression, so we can't likely fix it in SwiftCloudant, but keeping an issue here for awareness and tracking.

[ricellis]

This issue with the Swift runtime appears resolved since Swift 4.2 on Linux.