MiMeS: Misalignment mechanism solver

We introduce a C++ header-only library that is used to solve the axion equation of motion, MiMeS. MiMeS makes no assumptions regarding the cosmology and the mass of the axion, which allows the user to consider various cosmological scenarios and axion-like models. MiMeS also includes a convenient python interface that allows the library to be called without writing any code in C++, with minimal overhead.