circe-yaml 0.6.0

This release updates the circe version from 0.7.0 to 0.8.0 and the SnakeYAML version from 1.17 to 1.18.

It also fixes an issue with block and flow styles being reversed (#22; thanks @denisrosset) and adds a preserveOrder option that allows printers to use insertion order (#23; also thanks to @denisrosset). It also includes doc fixes (#20) and build updates (#25) by @jonas and @n4to4.

Note that because of a change in SnakeYAML 1.18, long strings may be split across lines when they weren't previously. If this isn't the behavior you want, you can set splitLines = false to ensure that it doesn't happen.