[DOC] Add examples of running Python unittests to docs

[r3stl355]

Description

Added an example of running Python tests in Conda environment

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

[mxnet-bot]

Hey @r3stl355 , Thanks for submitting the PR
All tests are already queued to run once. If tests fail, you can trigger one or more tests again with the following commands:

• To trigger all jobs: @mxnet-bot run ci [all]
• To trigger specific jobs: @mxnet-bot run ci [job1, job2]

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CI supported jobs: [miscellaneous, windows-gpu, unix-cpu, edge, unix-gpu, website, clang, sanity, centos-cpu, windows-cpu, centos-gpu]

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Note:
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All CI tests must pass before the PR can be merged.

[leezu]

When we build MXNet outside of conda and use it inside conda, there can be toolchain mismatch issues causing segfault or deadlock. For example, this is known to happen when building mxnet-horovod with mpi. The reason appears to be a conflict between statically linked libraries in the conda python binary and binaries linked by the mpi integration. See dmlc/gluon-nlp#1371 for details.

As we don't have any instructions for building mxnet with the conda toolchain, how about updating this PR to be independent of conda?

[r3stl355]

Sure, I'll remove conda

[r3stl355]

run ci [macosx-x86_64]

[r3stl355]

run ci [centos-cpu,centos-gpu, unix-cpu]

[r3stl355]

@mxnet-bot run ci [macosx-x86_64,centos-cpu,centos-gpu, unix-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [centos-cpu, centos-gpu, unix-cpu]

[leezu]

@mxnet-bot run ci [macosx-x86_64,centos-cpu,centos-gpu, unix-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [centos-gpu, unix-cpu, centos-cpu]

[leezu]

@mxnet-bot run ci [centos-cpu,centos-gpu, unix-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [centos-gpu, unix-cpu, centos-cpu]

[leezu]

@mxnet-bot run ci [edge]

[mxnet-bot]

Jenkins CI successfully triggered : [edge]

[szha]

Many thanks for the contribution, Nikolay!

[r3stl355]

Ahh, merged - thanks. I can now starting looking at something else