Have update_check.py also verify if it's on maven

[bombcar]

Running update_check.py we see:

Checking DetravScannerMod:1.6.4 for updates
Checking Draconic-Evolution:1.1.2 for updates
Checking Electro-Magic-Tools:1.2.8.6 for updates

but on Maven:

it should flag the ones that don't have a directory so I can go find and fix them.