issues: 325889600

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id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
325889600 MDU6SXNzdWUzMjU4ODk2MDA= 2177 Dataset.to_netcdf() cannot create group with engine="h5netcdf" 1200058 closed 0     1 2018-05-23T22:03:07Z 2018-05-25T00:52:07Z 2018-05-25T00:52:07Z NONE      

Code Sample, a copy-pastable example if possible

```python import pandas as pd import numpy as np import xarray as xr

sample_data = np.random.uniform(size=[2,2000,10000]) x = xr.Dataset({"sample_data": (("x", "y", "z"), sample_data)})

df = pd.DataFrame({"x": [1,2,3], "y": [2,4,6]}) x["df"] = df print(x)

not working:

x.to_netcdf("test.h5", group="asdf", engine="h5netcdf")

working:

x.to_netcdf("test.h5", group="asdf", engine="netcdf4")

```

Problem description

h5netcdf does not allow creating groups

Expected Output

should save data to "test.h5"

Output of xr.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 3.6.5.final.0 python-bits: 64 OS: Linux OS-release: 4.16.9-1-ARCH machine: x86_64 processor: byteorder: little LC_ALL: None LANG: de_DE.UTF-8 LOCALE: de_DE.UTF-8 xarray: 0.10.4 pandas: 0.22.0 numpy: 1.14.3 scipy: 1.0.1 netCDF4: 1.3.1 h5netcdf: 0.5.1 h5py: 2.7.1 Nio: None zarr: None bottleneck: 1.2.1 cyordereddict: None dask: None distributed: None matplotlib: 2.2.2 cartopy: None seaborn: None setuptools: 39.2.0 pip: 10.0.1 conda: None pytest: None IPython: 6.3.1 sphinx: None 
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   completed 13221727 issue

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