Unable to discover Boost.Python on Windows 10

[dzhoshkun]

None of the following as recommended seems to work:

582  history
  583  export BOOST_INCLUDEDIR=C:/Boost/boost_1_69_0
  584  export BOOST_LIBRARYDIR=C:/Boost/boost_1_69_0/stage/lib
  585  export BOOST_ROOT=C:/Boost/boost_1_69_0
  586  rm -rf ./*
  587  cmake ../../GIFT-Grab/src/cmake/boost.python/
  588  history
  589  rm -rf ./*
  590  cmake -D BOOST_ROOT=C:/Boost/boost_1_69_0 -D BOOST_INCLUDEDIR=C:/Boost/boost_1_69_0 -D BOOST_LIBRARYDIR=C:/Boost/boost_1_69_0/stage/lib ../../GIFT-Grab/src/cmake/boost.python/
  591  history

The error message is:

CMake Error at C:/Program Files/CMake/share/cmake-3.12/Modules/FindBoost.cmake:2048 (message):
  Unable to find the requested Boost libraries.

  Boost version: 1.69.0

  Boost include path: C:/Boost/boost_1_69_0

  Could not find the following Boost libraries:

          boost_python

  No Boost libraries were found.  You may need to set BOOST_LIBRARYDIR to the
  directory containing Boost libraries or BOOST_ROOT to the location of
  Boost.
Call Stack (most recent call first):
  CMakeLists.txt:7 (FIND_PACKAGE)


-- Configuring incomplete, errors occurred!
See also "C:/Users/dzhoshkun/ws/_b/gg-boost/CMakeFiles/CMakeOutput.log".

[dzhoshkun]

• above failure due to Build against Python 3.7 on Windows 10 #81

[dzhoshkun]

The above commit fixes this issue.