pinned pytest cov version to fix build issues with old travis dependencies
pinned pytest cov version to fix build issues with old travis dependencies

RosesTheN00b/BudgetButlerWeb,RosesTheN00b/BudgetButlerWeb,RosesTheN00b/BudgetButlerWeb,RosesTheN00b/BudgetButlerWeb,RosesTheN00b/BudgetButlerWeb,RosesTheN00b/BudgetButlerWeb