build(libvsc): Update to 0.5.0a1 (built via poetry)

Author: tony

poetry.lock

@@ -44,7 +44,7 @@ vcspull = 'vcspull:cli.cli'
 python = "~2.7 || ^3.5"
 click = ">=7<8"
 kaptan = "*"
-libvcs = "^0.4.4"
+libvcs = { version = "0.5.0a1", allow-prereleases = true }
 colorama = ">=0.3.9"
 
 [tool.poetry.dev-dependencies]