Also add stacklevel

…alse

* upstream/master:
  add missing pint integration tests (pydata#3508)
  DOC: update bottleneck repo url (pydata#3507)
  add drop_sel, drop_vars, map to api.rst (pydata#3506)
  remove syntax warning (pydata#3505)
  Dataset.map, GroupBy.map, Resample.map (pydata#3459)
  tests for datasets with units (pydata#3447)
  fix pandas-dev tests (pydata#3491)
  unpin pseudonetcdf (pydata#3496)
  whatsnew corrections (pydata#3494)
  drop_vars; deprecate drop for variables (pydata#3475)
  uamiv test using only raw uamiv variables (pydata#3485)
  Optimize dask array equality checks. (pydata#3453)

…o fix/user-coordinates

* 'fix/user-coordinates' of github.com:dcherian/xarray:

* upstream/master:
  Allow appending datetime & boolean variables to zarr stores (pydata#3504)
  warn if dim is passed to rolling operations. (pydata#3513)
  Deprecate allow_lazy (pydata#3435)
  Recursive tokenization (pydata#3515)
  format indexing.rst code with black (pydata#3511)

* upstream/master: (35 commits)
  fix plotting with transposed nondim coords. (pydata#3441)
  make coarsen reductions consistent with reductions on other classes (pydata#3500)
  Resolve the version issues on RTD (pydata#3589)
  Add bottleneck & rasterio git tip to upstream-dev CI (pydata#3585)
  update whats-new.rst (pydata#3581)
  Examples for quantile (pydata#3576)
  add cftime intersphinx entries (pydata#3577)
  Add pyXpcm to Related Projects doc page (pydata#3578)
  Reimplement quantile with apply_ufunc (pydata#3559)
  add environment file for binderized examples (pydata#3568)
  Add drop to api.rst under pending deprecations (pydata#3561)
  replace duplicate method _from_vars_and_coord_names (pydata#3565)
  propagate indexes in to_dataset, from_dataset (pydata#3519)
  Switch examples to notebooks + scipy19 docs improvements (pydata#3557)
  fix whats-new.rst (pydata#3554)
  Tweaks to release instructions (pydata#3555)
  Clarify conda environments for new contributors (pydata#3551)
  Revert to dev version
  0.14.1 whatsnew (pydata#3547)
  sparse option to reindex and unstack (pydata#3542)
  ...

…o fix/user-coordinates

* 'fix/user-coordinates' of github.com:dcherian/xarray: