Adjust main check to look for new Element type

[evancz]

No description provided.

[zgotsch]

Hey @evancz, I am seeing an error that seems like it could be related to this:

The 'main' value has an unsupported type.

52│ main : Signal Element
    ^^^^^^^^^^^^^^^^^^^^^
I need an Element, Html, (Signal Element), or (Signal Html) so I can render it
on screen, but you gave me:

    Signal Element

Detected errors in 1 module.

This is in the release version of 0.16. The code was working in one of the release candidates for 0.16, but broke when I upgraded. Is there a thread about this somewhere?

[zgotsch]

Immediately after typing this I realized it was probably a problem with my libs. Running elm-package install didn't do anything, but blowing away elm-stuff and reinstalling packages fixed my problem.