Switch to using Python 3.8 on travis (also update dist for that); still testing 2.7, 3.6, 3.7 with crucial tests
Switch to using Python 3.8 on travis (also update dist for that); still testing 2.7, 3.6, 3.7 with crucial tests

jobovy/galpy,jobovy/galpy,jobovy/galpy,jobovy/galpy