Fix build docs script
Fix build docs script

Summary:
Fixed build-docs script. Workaround for #373
Closes https://github.com/Instagram/IGListKit/pull/447

Differential Revision: D4479613

Pulled By: rnystrom

fbshipit-source-id: abc61ed11ae01efbbe9b5aaab2036501d269f9c7

Instagram/IGListKit,zhubofei/IGListKit,charles0126dev/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,dshahidehpour/IGListKit,charles0126dev/IGListKit,dshahidehpour/IGListKit,zhubofei/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,Instagram/IGListKit,dshahidehpour/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,charles0126dev/IGListKit