New Features
* New estimators (`frites.estimator.CorrEstimator`, `frites.estimator.DcorrEstimator`) for continuous / continuous relationships (73ed8bbb, bc370a93, cf7a3456f)
* `frites.conn.conn_dfc` supports passing other estimators (a864a7b05b)
* `frites.utils.time_to_sample` and `frites.utils.get_closest_sample` conversion functions (7c44478e)
* `frites.conn.conn_ravel_directed` reshaping function (f9b9d272)
* new `frites.workflow.WfMi.copy` for internal workflow copy (0c2228c7, 860f3d45)
* new `frites.workflow.WfMiCombine` and example class for combining workflows (62072ee52)
* new class`frites.estimator.ResamplingEstimator` trial-resampling estimator (13f6271e)
Bug fixes
* Fix `frites.workflow.WfMi.get_params` when returning a single output (3bde82e6)
* Improve attributes conversion for saving netcdf files (bool and dict) (8e7dddb1, c6f7a4db)
* Fix Numpy `np.float` and `np.int` warnings related (896a198a, 7f2a1caef, 0d1a1223)