implemented single and global uniform takestep and adaptive takestep, adjusted tests and added some tests, more needed
bug fix to single particle move and written several tests to test new class
removed layer in c++ random_coords_displacement, wrapped, adapted mcrunner and added mcrunner test
Merge branch 'master' of https://github.com/pele-python/mcpele into single_random_coords_displacement
Merge pull request #45 from pele-python/single_random_coords_displacement

Single random coords displacement