Fluoscenepy

Fixed
- Issue with generation of subpixel particles, when mean size ~ 2 or fewer pixels and STD is ~ 1 pixel.
- Improved README text content.

Overall acceleration of computation and object placement methods.
Added
- Method (check API documentation): *get_objects_acc*
- More printouts if methods for *UscopeScene* called with *verbose_info* flag
- Automatic acceleration in the method *set_random_places* if **numba** installed.

Initial release with 2 implemented simulation classes:
*UscopeScene* - for simulation of a microscopic image;
*FluorObj* - for simulation of an individual bead / elongated small continuously-shaped fluorescent object;
Added
- Initial release with functionality revealed in API Documentation and README;