Merge branch 'master' of https://github.com/deepchem/deepchem into padding

   conda install -c omnia mdtraj

   ```

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

13. `scikit-learn`

    ```bash

    conda install scikit-learn 

    ```

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

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

    ```bash

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

    ```

    python setup.py install

    ```

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

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

    ```bash

    pip install nose 

    ```

    Make sure that the correct version of `nosetests` is active by running

    ```bash

    which nosetests 

    ```

    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:

    ```bash

    nosetests -v deepchem --nologcapture 

    ```