Fix readthedocs build

Author: maciejlach

setup.py

@@ -17,9 +17,14 @@
 from distutils.core import setup
 from qpython import __version__
 
-import numpy
 import os
 
+try:
+    import numpy
+    include_dirs = [numpy.get_include()]
+except:
+    include_dirs = []
+
 try:
     from Cython.Build import cythonize
 except ImportError:
@@ -49,7 +54,7 @@ def read(fname):
       license = 'Apache License Version 2.0',
 
       ext_modules = ext_modules,
-      include_dirs = [numpy.get_include()],
+      include_dirs = include_dirs,
 
       keywords = ['kdb+', 'q'],
       classifiers=[