Fails to install on os X 10.10.5
Installing with `nimble install aporia` gives me this error

``````
Error: execution of an external compiler program 'clang -c  -w -pthread -O3  -I/Volumes/gernest/Nim/lib -o /private/tmp/nimble_80149/githubcom_nimlangAporia/nimcache/aporia_aporia.o /private/tmp/nimble_80149/githubcom_nimlangAporia/nimcache/aporia_aporia.c' failed with exit code: 256

/private/tmp/nimble_80149/githubcom_nimlangAporia/nimcache/dialogs_dialogs.m:622:52: error: property 'path' not found on object of type 'id'
        cres0[i] = [dialog0.URLs objectAtIndex: i].path.UTF8String;
                                                   ^
/private/tmp/nimble_80149/githubcom_nimlangAporia/nimcache/dialogs_dialogs.m:688:47: error: property 'path' not found on object of type 'id'
      cres0 = [dialog0.URLs objectAtIndex: 0].path.UTF8String;
                                              ^
2 errors generated.
Build failed for 'aporia@0.4.1', would you like to try installing 'aporia@#head' (latest unstable)? [y/N]```
``````
