Fix the way environment variable is passed to ejson

[casperisfine]

We just noticed this with @DazWorrall. In our environment EJSON_KEYDIR is set, and the way this code works right now doesn't allow to override existing env:

>> out, err, st = Open3.capture3({ 'EJSON_KEYDIR' => 'foo' }, "EJSON_KEYDIR=bar echo $EJSON_KEYDIR")
=> ["foo\n", "", #<Process::Status: pid 11963 exit 0>]

It's much better to pass the env as a hash, and the command arguments as variadic arguments anyway, as it avoid having to spawn a shell to parse the command.

[timothysmith0609]

🚢

[RyanBrushett]

⛵