0.9

This is a stable release based on the following unstable dependencies:

• Cats Effect v1.0.0-RC2
• Circe v0.10.0-M1
• Fs2 v1.0.0-M1

Including the following contributions:

• #69 Add deliveryMode and priority to message props by @jacemale
• #73 Relaxing constraints by @danielkarch
• #75 Custom JSON printer by @ybasket
• #76 Support for array headers by @orium

Thank you all!