shebang is not valid for Linux, cli fails to run

[jxn]

shebang does not take arguments on most linuxes, which makes the cli fail to run with an error for most linux users:

$ observatory somesite.com
/usr/bin/env: ‘node --harmony’: No such file or directory

modifying the shebang in index.js should fix it: #!/usr/bin/env node, but I don't know what the repercussions are for other platforms or why --harmony is being used