Install error with Python 3.6 on Windows

[QuinRiva]

psutil 4.3.0 doesn't appear to be available for python 3.6, and the Windows compiler throws an error when attempting to install (error message at end).

Newer versions of psutil install fine, but datalab has a psutil=4.3.0 dependency.

Creating a python 3.5 environment datalab installs fine.

` psutil/_psutil_windows.c(866): warning C4267: '=': conversion from 'size_t' to 'DWORD', possible loss of data
psutil/_psutil_windows.c(1431): warning C4267: '=': conversion from 'size_t' to 'ULONG', possible loss of data
psutil/_psutil_windows.c(1432): warning C4267: '=': conversion from 'size_t' to 'ULONG', possible loss of data
psutil/_psutil_windows.c(2004): warning C4312: 'type cast': conversion from 'int' to 'PVOID' of greater size
psutil/_psutil_windows.c(2703): error C2039: 'ContextSwitches': is not a member of '_SYSTEM_THREAD_INFORMATION'
C:\Program Files (x86)\Windows Kits\10\include\10.0.16299.0\um\winternl.h(286): note: see declaration of '_SYSTEM_THREAD_INFORMATION'
psutil/_psutil_windows.c(2807): warning C4311: 'type cast': pointer truncation from 'PVOID' to 'unsigned long'
error: command 'C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.12.25827\bin\HostX64\x64\cl.exe' failed with exit status 2

----------------------------------------

Command "C:\ProgramData\Anaconda3\python.exe -u -c "import setuptools, tokenize;file='C:\Users\username\AppData\Local\Temp\pip-build-gscj_lcr\psutil\setup.py';f=getattr(tokenize, 'open', open)(file);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, file, 'exec'))" install --record C:\Users\username\AppData\Local\Temp\pip-y9vha2m9-record\install-record.txt --single-version-externally-managed --compile" failed with error code 1 in C:\Users\username\AppData\Local\Temp\pip-build-gscj_lcr\psutil`

[QuinRiva]

This does appear to be an issue exclusive to windows, installation occurs fine with Anaconda 5.0.1 and Python 3.6 under an Ubuntu sandbox within Windows 10.

Also an Anaconda virtual environment running python 3.5 under Windows seems to work as well (a psutil 4.3.0 package is available for python 3.5).

Can datalab be updated to support more recent versions of psutil?

[chmeyers]

I don't have a Windows machine to test this on currently, but I'll accept a pull request from somebody that does.