requirements.txt uses peep format

peep is deprecated and shouldn't be used if at least pip 8 is available (even stretch has pip 9 already). Also, it sets --no-index which prevents it from working and --no-use-wheel which is unnecessary when using pip.

This could be the file:

pysqlite==2.6.3 --hash=sha256:fe9c35216bf56c858b34c4b4c8be7e34566ddef29670e5a5b43f9cb8ecfbb28d
SQLAlchemy==0.7.10 --hash=sha256:77aa39d65c9d043eba6ba329b359ff867424fd6c403b7c0cb112b65e507e1d66
Elixir==0.7.1 --hash=sha256:a7ef437f25b544e4f74fb3236fc43cd25f5d6feb6037dd7c66931046d75439e9