[PIN] Force numpy>=1.15.4 when Python>=3.7

Addresses the [numpy
bug](https://www.opensourceanswers.com/blog/you-shouldnt-use-python-37-for-data-science-right-now.html).

Author: oesteban

nipype/info.py

@@ -101,7 +101,9 @@ def get_nipype_gitversion():
 # versions
 NIBABEL_MIN_VERSION = '2.1.0'
 NETWORKX_MIN_VERSION = '1.9'
-NUMPY_MIN_VERSION = '1.9.0'
+# Numpy bug in python 3.7:
+# https://www.opensourceanswers.com/blog/you-shouldnt-use-python-37-for-data-science-right-now.html
+NUMPY_MIN_VERSION = '1.9.0' if sys.version_info < (3, 7) else '1.15.4'
 SCIPY_MIN_VERSION = '0.14'
 TRAITS_MIN_VERSION = '4.6'
 DATEUTIL_MIN_VERSION = '2.2'