Clean install_via_conda (#1097)

Summary:
Circle CI job `test_conda` is failing because of some missing dependencies, like
```
E   ImportError: libtiff.so.5: cannot open shared object file: No such file or directory
```

The cause is that when we install `nodejs`  through conda, it will upgrade some packages, like
```
> conda install -y --no-channel-priority -c conda-forge nodejs=14

...
libtiff                                  4.3.0-hf544144_1 --> 4.5.0-h82bc61c_0
```
The newer version is not be compatible with some python packages.

Downgrade those incompatible packages will fix the issue. But I made this PR to just drop the installations of `nodejs` and `yarn`  (and some other unused packages like `mypy` `flake8`). Also stop building `captum-insight`

I feel `nodejs` & `yarn` are used for building the website and Insight's frontend. However, this script is only used in for CircleCI's conda testing, which does not execute anything related to Insight frontend or build website, so it safe to remove them.

(I am not sure why we include them in the 1st place. Let me know if I missed some use cases of this script)

Pull Request resolved: #1097

Reviewed By: vivekmig

Differential Revision: D42201597

Pulled By: aobo-y

fbshipit-source-id: a57a13a76176ffa47e5728d6359410c2f599ba24

Author: aobo-y

scripts/install_via_conda.sh

@@ -39,18 +39,8 @@ else
 fi
 
 # install other deps
-# conda install -y numpy sphinx pytest flake8 ipywidgets ipython scikit-learn parameterized
-# conda install -y -c conda-forge matplotlib pytest-cov sphinx-autodoc-typehints mypy flask flask-compress
-conda install -y pytest flake8 ipywidgets ipython scikit-learn parameterized
-conda install -y -c conda-forge matplotlib pytest-cov mypy flask flask-compress
+conda install -y pytest ipywidgets ipython scikit-learn parameterized
+conda install -y -c conda-forge matplotlib pytest-cov flask flask-compress
 
-# deps not available in conda
-# pip install sphinxcontrib-katex
-
-# install node/yarn for insights build
-conda install -y -c conda-forge yarn
-# nodejs should be last, otherwise other conda packages will downgrade node
-conda install -y --no-channel-priority -c conda-forge nodejs=14
-
-# build insights and install captum
-BUILD_INSIGHTS=1 python setup.py develop
+# install captum
+python setup.py develop