Change the logic around how we load our config.

The previous logic that was intended to find the first non-empty
filename that represented a valid file location was wrong. Replaced with
a simpler filter-based version.

Additionally, if the user provides a specific configuration filename, we
no longer fall back to the defaults if it is not found. Instead we just
err out and inform them that the file the specified was not found.

ptk.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version       = "1.0.13"
+version       = "1.0.14"
 author        = "Jonathan Bernard"
 description   = "Personal Time Keeper"
 license       = "MIT"