BUG: print_versions uses path python rather then the invoking python

Author: y-p

ci/print_versions.py

@@ -2,15 +2,15 @@
 
 
 def show_versions():
-    import subprocess
+    import imp
     import os
     fn = __file__
     this_dir = os.path.dirname(fn)
     pandas_dir = os.path.abspath(os.path.join(this_dir,".."))
-    sv_path = os.path.join(pandas_dir, 'pandas', 'util',
-                            'print_versions.py')
-    return subprocess.check_call(['python', sv_path])
+    sv_path = os.path.join(pandas_dir, 'pandas','util')
+    mod = imp.load_module('pvmod', *imp.find_module('print_versions', [sv_path]))
+    return mod.show_versions()
 
 
 if __name__ == '__main__':
-    show_versions()
+    return show_versions()