bump pants version to 2.14.0rc1

I used 2.14 for the PoC due to some features that simplify
the pants configuration. Ideally, 2.14.0 final will be released
in a month or so, while we finalize the st2 dev docs.

This should be the final piece before we can run ./pants tailor.

Author: cognifloyd

pants.toml

@@ -1,5 +1,5 @@
 [GLOBAL]
-pants_version = "2.13.0rc2"
+pants_version = "2.14.0rc1"
 backend_packages = [
   # python
   "pants.backend.python",