Update ISSUE_TEMPLATE.md (#1462)
Update ISSUE_TEMPLATE.md (#1462)

Summary:
add a field to ask people how they installed Faiss

Pull Request resolved: https://github.com/facebookresearch/faiss/pull/1462

Reviewed By: LowikC

Differential Revision: D24279581

Pulled By: mdouze

fbshipit-source-id: 2492c73e31d22f3b7f37de6bcfcac90eae0ccd07

facebookresearch/faiss,facebookresearch/faiss,facebookresearch/faiss,facebookresearch/faiss