Add missing "importPaths" field.

When using "ncurses" as a DUB dependency, the compiler was complaining than the `deimos.ncurses.*` modules couldn't be found, because the proper `-I` compiler switch was missing. This change fixes it.

A cleaner solution would be to move the "deimos/" directory into a separate "source/" folder, so that the .d files in the "examples/" folder are outside of the import path.