Update Scala Macros to stable 2.0.0

Scala Macros (paradise and quasiquotes) have reached a stable 2.0.0 version. Between M3 and the stable version, there's been a refactor that cause [cross-version conflicts between libraries with no great workaround][1]. For example, it is currently not possible to compile a project using both Monocle and Spire, which uses the 2.0.0 release of Scala Macros.

This updates each of the libraries and fixes a small API change.

[1]: http://stackoverflow.com/a/23150477