Prune old requirements and add pylint command.

* [sklearn](https://github.com/scikit-learn/scikit-learn.git)

* [numpy](https://store.continuum.io/cshop/anaconda/)

* [keras](http://keras.io)

* [six](https://pypi.python.org/pypi/six)

* [dill](https://pypi.python.org/pypi/dill)

* [ipyparallel](https://ipyparallel.readthedocs.io/en/latest/)

* [mdtraj](http://mdtraj.org/)

* [tensorflow](https://www.tensorflow.org/)

   ```

   See [keras docs](https://keras.io/backend/) for more details and alternate methods of setting backend.

8. `six`

   ```bash

   conda install six

   ```

9. `dill`

    ```bash

    conda install dill

    ```

10. `ipyparallel`

    ```bash

    conda install ipyparallel

    ```

11. `mdtraj`

8. `mdtraj`

   ```bash

   conda install -c omnia mdtraj

   ```

12. `scikit-learn`

9. `scikit-learn`

   ```bash

   conda install scikit-learn 

   ```

13. `tensorflow`: Installing `tensorflow` on older versions of Linux (which

10. `tensorflow`: Installing `tensorflow` on older versions of Linux (which

    have glibc < 2.17) can be very challenging. For these older Linux versions,

    contact your local sysadmin to work out a custom installation. If your

    version of Linux is recent, then the following command will work:

    conda install -c https://conda.anaconda.org/jjhelmus tensorflow

    ```

14. `h5py`:

11. `h5py`:

    ```

    conda install h5py

    ```

15. `deepchem`: Clone the `deepchem` github repo:

12. `deepchem`: Clone the `deepchem` github repo:

    ```bash

    git clone https://github.com/deepchem/deepchem.git

    ```

    python setup.py install

    ```

16. To run test suite, install `nosetests`:

13. To run test suite, install `nosetests`:

    ```bash

    pip install nose --user

    ```

    You might need to uninstall a system install of `nosetests` if

    there is a conflict.

17. If installation has been successful, all tests in test suite should pass:

14. If installation has been successful, all tests in test suite should pass:

    ```bash

    nosetests -v deepchem --nologcapture 

    ```

Once you've got a sense of how the package works, we encourage the use of Github issues to discuss more complex changes,  raise requests for new features or propose changes to the global architecture of DeepChem. Once consensus is reached on the issue, please submit a PR with proposed modifications. All contributed code to DeepChem will be reviewed by a member of the DeepChem team, so please make sure your code style and documentation style match our guidelines!

### Code Style Guidelines

DeepChem broadly follows the [Google Python Style Guide](https://google.github.io/styleguide/pyguide.html). In terms of practical changes, the biggest effect is that all code uses 2-space indents instead of 4-space indents. We encourage new contributors to make use of [pylint](https://www.pylint.org/). Aim for a score of at least 8/10 on contributed files.

DeepChem broadly follows the [Google Python Style Guide](https://google.github.io/styleguide/pyguide.html). In terms of practical changes, the biggest effect is that all code uses 2-space indents instead of 4-space indents. We encourage new contributors to make use of [pylint](https://www.pylint.org/) with the following command

```

pylint --disable=invalid-name --indent-string "  " --extension-pkg-whitelist=numpy [file.py]

```

Aim for a score of at least 8/10 on contributed files.

### Documentation Style Guidelines

DeepChem uses [NumPy style documentation](https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt). Please follow these conventions when documenting code, since we use [Sphinx+Napoleon](http://www.sphinx-doc.org/en/stable/ext/napoleon.html) to automatically generate docs on [deepchem.io](deepchem.io).