excessive amount of build warnings and errors

[aaronmarkham]

There are over 100-200k build warnings.

copying static files... done
copying extra files... done
dumping search index in English (code: en) ... done
dumping object inventory... done
build succeeded, 209299 warnings.

Here are some samples:

Failed to import:

WARNING: [autosummary] failed to import 'mxnet.io.DataIter': no module named mxnet.io.DataIter

Pandoc version warning:

  nbconvert.utils.pandoc.check_pandoc_version()
/home/markhama/anaconda3/envs/mxnet-docs/lib/python3.7/site-packages/nbsphinx.py:1174: RuntimeWarning: You are using an unsupported version of pandoc (2.2.3.2).
Your version must be at least (1.12.1) but less than (2.0.0).
Refer to http://pandoc.org/installing.html.
Continuing with doubts...

Failed to import module:

WARNING: autodoc: failed to import module 'ndarray.sparse' from module 'mxnet'; the following exception was raised:
...
OSError: /lib64/libc.so.6: version `GLIBC_2.16' not found (required by /home/markhama/anaconda3/envs/mxnet-docs/lib/python3.7/site-packages/mxnet/libmxnet.so)

Failed to import class:

WARNING: autodoc: failed to import class 'ndarray.sparse.CSRNDArray' from module 'mxnet'; the following exception was raised:
...
OSError: libcudart.so.9.2: cannot open shared object file: No such file or directory

Failed to import module:

WARNING: autodoc: failed to import module 'monitor' from module 'mxnet'; the following exception was raised:

Unknown document:

/home/ubuntu/new-docs/python/build/api/symbol/mxnet.symbol.Symbol.rst:302: WARNING: toctree references unknown document 'api/symbol/_autogen/Symbol.debug_str'

Failed to import:

/home/ubuntu/new-docs/python/build/api/symbol/mxnet.symbol.Symbol.rst:314: WARNING: failed to import Symbol.clip

Toctree contains reference to nonexisting document:

/home/ubuntu/new-docs/python/build/guide/index.rst:132: WARNING: toctree contains reference to nonexisting document 'guide/   image/index'

File not found:

/home/ubuntu/new-docs/python/build/guide/modules/gluon/custom-layer.ipynb:25: WARNING: File not found: 'guide/modules/gluon/model-construction.md'

[aaronmarkham]

I reduced warnings/errors from 200k to 2k by getting rid of random.seed in the docs. This can/should be added later when/if someone knows how to include it without causing so many warnings.