Use proper capitalization in require()

Hello @evansolomon, 

Please review the following commits I made in branch 'es-fix-ci-fails'.

28504977733b076bec4d27cf0f0564377a2cdb5f (2013-09-04 17:45:29 -0700)
Use proper capitalization in require()
Apparently OSX's filesystem is lenient about this


R=@evansolomon