Unable to install keybase-installer as root

First attempting to install `keybase-installer` as `root` fails with the error

```
error: exit code 2
```

I'm unable to tell from the debug output the cause. I'm unsure why it reports a file open error. Maybe an issue with spaces in the directory?

```
$ sudo keybase-installer -d
debug: + cmd.run 1.0.1

...

debug: || Mutate GPG args; new args: --no-default-keyring --keyring /home/gene/.keybase-installer/keyring/pubring.gpg --secret-keyring /home/gene/.keybase-installer/keyring/secring.gpg --trustdb-name /home/gene/.keybase-installer/keyring/trustdb.gpg -k --with-fingerprint --with-colons
debug: +++ cleanup /tmp/keybase_install_9WzdFIVBheTXhWHoidk4LA
info: cleaning up tmpdir /tmp/keybase_install_9WzdFIVBheTXhWHoidk4LA
debug: --- cleanup /tmp/keybase_install_9WzdFIVBheTXhWHoidk4LA -> OK
error: exit code 2
warn: gpg: WARNING: unsafe ownership on configuration file `/home/jdoe/.gnupg/gpg.conf'
warn: gpg: keyblock resource `/home/jdoe/Documents/Keys and Certs/gpg/secring.gpg': file open error
warn: gpg: keyblock resource `/home/jdoe/Documents/Keys and Certs/gpg/pubring.gpg': file open error
warn: gpg: keyblock resource `/home/jdoe/Documents/Keys and Certs/gpg/pubring.gpg': file open error
```

Start by reproducing the reported `sudo keybase-installer -d` command and inspect how the installer invokes GPG and selects its keyring paths. Trace the reported file-open errors involving spaces in the directory and the root user's environment; done means installation no longer exits with code 2 when run as root.

Written by the indexing model from the issue text.