Update :artifacts doc string
Normalize output of 'resolve-artifacts

Calling (resolve-artifacts :from-maven-repo ...)
was returning artifacts such as:

[{:local-file #<java.io.File> ...} ...].

'pallet.crate.app-deploy/deploy passes these maps to 'remote-file,
however 'remote-file has a schema, 'remote-file-arguments, that stipulates
:local-file string?
Updated metadata for 0.8.0-alpha.3
Updated project.clj, release notes and readme for 0.8.0-alpha.3
Merge branch 'release/0.8.0-alpha.3'
Merge tag '0.8.0-alpha.3' into develop

app-deploy-0.8.0-alpha.3
Updated version for next release cycle