Merge tag '0.8.0-alpha.3' into develop

riemann-crate-0.8.0-alpha.3
Updated version for next release cycle
Update default version
Add configuration for instrumentation
Use lein-pallet-release
Make clojure and pallet :provided scoped
Updated project.clj, release notes and readme for 0.8.0-alpha.4
Merge release/0.8.0-alpha.4