class for runs in a binary sequence
Parameters:  x : array_like, 1d


Notes
This was written as a more general class for runs. This has some redundant calculations when only the runs_test is used.
TODO: make it lazy
The runs test could be generalized to more than 1d if there is a use case for it.
This should be extended once I figure out what the distribution of runs of any length k is.
The exact distribution for the runs test is also available but not yet verified.
Methods
runs_test([correction])  basic version of runs test 