Use escape() instead of encodeURI()

Although escape is deprecated and should be replaced by encodeURI, Embed.ly still expects it to be used.

Using encodeURI on a google map url like:
https://www.google.com/maps/@39.8146794,-97.4038736,19z

results in a 404, whereas escape returns the expected output.
Merge pull request #9 from sethlesky/patch-1

Use escape() instead of encodeURI()