compile errors on fresh clone

[srochel]

following instructions in install.md trying to build and install on MAC 10.11.6

1. git clone --recursive ...
   is missing dmlc-core and dlpack

2. by default USE_CUDA=1, which requires cuda libraries. Lack of cuda libraries results in compile error

3. installation for user failed, system wide installation worked.
   python setup.py install --user
   ['/Users/steroche/Documents/Projects/TVM/tvm/lib/libtvm.so']
   Warning: Extension name 'tvm._ffi._cy2.core' does not match fully qualified name 'core' of 'tvm/_ffi/_cython/core.pyx'
   Compiling tvm/_ffi/_cython/core.pyx because it changed.
   [1/1] Cythonizing tvm/_ffi/cython/core.pyx
   running install
   error: can't combine user with prefix, exec_prefix/home, or install(plat)base
   c4b301cf6ca3:python steroche$ ll /Users/steroche/Documents/Projects/TVM/tvm/lib/libtvm.so
   -rwxr-xr-x 1 steroche ANT\Domain Users 7334320 Jul 9 12:15 /Users/steroche/Documents/Projects/TVM/tvm/lib/libtvm.so
   c4b301cf6ca3:python steroche$ vim setup.py
   c4b301cf6ca3:python steroche$ sudo python setup.py install

[tqchen]

#262