What's Changed
* Added aliases to solvers:
* ``ise`` for ``isentropic_solver``.
* ``fan`` for ``fanno_solver``.
* ``ray`` for ``rayleigh_solver``.
* ``ss`` for ``shockwave_solver``.
* ``css`` for ``conical_shockwave_solver``.
* Added Aerothermodynamic module (``pygasflow.atd``):
* correlations to compute boundary layer thickness, heat flux, wall shear stress.
* functions to compute the pressure distribution and aerodynamic characteristics with the Newtonian (and modified Newtonian) flow theory.