Update CMakeLists.txt
Update README.md

Last: #576
Merge pull request #644 from DavidRagazzi/patch-1

Update CMakeLists.txt
Merge branch 'master' into travis-cmake
Merge branch 'patch-3' of github.com:DavidRagazzi/nupic into test-cmake
Allow Travis-CI to update submodule itself.

Also adds instruction to README to expand submodule manually during a
manual build. Also updates build.sh script to assume this was done
manually.
adding cd into travis build before make
Merge branch 'test-cmake' into david-patch-2