travis: add pytest (for test_curves.py)
travis: add pytest (for test_curves.py)

jhoenicke/trezor-crypto,romanz/trezor-crypto,01BTC10/trezor-crypto,jhoenicke/trezor-crypto,trezor/trezor-crypto,romanz/trezor-crypto,01BTC10/trezor-crypto,jhoenicke/trezor-crypto,runn1ng/trezor-crypto,jhoenicke/trezor-crypto,trezor/trezor-crypto,trezor/trezor-crypto,romanz/trezor-crypto,01BTC10/trezor-crypto,runn1ng/trezor-crypto,romanz/trezor-crypto,runn1ng/trezor-crypto,jhoenicke/trezor-crypto,trezor/trezor-crypto,trezor/trezor-crypto,romanz/trezor-crypto,runn1ng/trezor-crypto,runn1ng/trezor-crypto