fix alphaepsilon issue
- set version to 0.1.2 in setup.cfg
- fix alphaepsilon issue when using MannTurbulenceField.generate(..., cache_spectral_tensor=True)
- always use alphaepsilon=1 when generating spectral tensor (makes it easier to reuse saved spectral tensors)
- add test of alphaepsilon when using MannTurbulenceField.generate(..., cache_spectral_tensor=True)
- remove egg-info files from git