Improve logs when Functions/publish directories are specified

[ehmicky]

When publishPath is specified, we should not print:

next-on-netlify/lib/steps/prepareFolders.js

Line 9 in 66cc4ce

log(" ", "Publish directory: ", publishPath);

since this is most likely taken from the site's already configured publish path, and the user would expect that to be used.

When functionsPath is specified, we should not print:

next-on-netlify/lib/steps/prepareFolders.js

Line 8 in 66cc4ce

log(" ", "Functions directory: ", functionsPath);

If both are specified, we should not print:

next-on-netlify/lib/steps/prepareFolders.js

Line 10 in 66cc4ce

log(" ", "Make sure these are set in your netlify.toml file.");

[ehmicky]

Fixed by #100