Handle opn errors better

[mrosack]

from rollbar:

Error: Exited with code 1
at ChildProcess. (C:\Users\Mike\AppData\Local\playyourdamnturn\app-1.1.11\resources\app.asar\node_modules\opn\index.js line 83 col 13)
at ChildProcess.g (events.js line 286 col 16)
at emitTwo (events.js line 106 col 13)
at ChildProcess.emit (events.js line 191 col 7)
at maybeClose (internal/child_process.js line 877 col 16)
at Socket. (internal/child_process.js line 334 col 11)
at emitOne (events.js line 96 col 13)
at Socket.emit (events.js line 188 col 7)
at Pipe._handle.close [as _onclose] (net.js line 493 col 12)

[mrosack]

fixed in de2c82c