Properly escape command line arguments in error log

[charlespierce]

Currently, the command-line arguments written to the error log are not escaped. That means, if you run:

notion install "node 10"

What gets written to the error log is:

/Users/me/.notion/notion install node 10

Which doesn't actually match the command that was run. We should correctly escape the command-line arguments if possible, so that the error log accurately reproduces the command that was run leading to the error.