Add Python 3.7 and 3.10 to Travis CI config.
Add Python 3.7 and 3.10 to Travis CI config.

Signed-off-by: Oleg Girko <665b39a1e96a9a15fc99f73183af3f04bf8111eb@infoserver.lv>

dashpay/dash_hash,dashpay/dash_hash,dashpay/dash_hash