This is a fix to the bug #99 by adding the function abs() to the denominator of the parametrization for t_E and the corresponding unit test. With the correction, the t_E value will always be positive even if u_0 is negative.
@rapoliveira Please make one more change: update the version number. It's kept in source/MulensModel/version.py. You have not modified the API, so in X.Y.Z you should increase Z by 1.
This is a fix to the bug #99 by adding the function abs() to the denominator of the parametrization for t_E and the corresponding unit test. With the correction, the t_E value will always be positive even if u_0 is negative.