Allowing syncing folders with 'init' in the root

[LPGhatguy]

This is kind of an extension of #57.

If your partition targets a folder that contains an init.lua or such file, you'll get a stack trace that isn't fun:

16:05:26.890 - Unhandled promise rejection:
16:05:26.891 - 
16:05:26.892 - Plugin_1211549683.Rojo.plugin.Reconciler:185: attempt to call method 'FindFirstChild' (a nil value)
16:05:26.892 - 
16:05:26.893 - Stack Begin
16:05:26.894 - Script 'Plugin_1211549683.Rojo.modules.Promise', Line 81 - field new
16:05:26.894 - Script 'Plugin_1211549683.Rojo.modules.Promise', Line 166 - method andThen
16:05:26.894 - Script 'Plugin_1211549683.Rojo.plugin.Plugin', Line 135 - method _pull
16:05:26.895 - Script 'Plugin_1211549683.Rojo.plugin.Plugin', Line 253
16:05:26.896 - Stack End

This should be supported!

[LPGhatguy]

The more that I think about this, the more I wonder how good of an idea it is.

What happens if you sync that same partition into, say, ReplicatedStorage?

[LPGhatguy]

This actually does work, the stack trace was because I typo'd a service name, which was fixed in a related issue.