Corrected installation

setup.py

@@ -1,10 +1,18 @@
 #!/usr/bin/env python
 
+from __future__ import print_function
 from distutils.core import setup
 from distutils.command.install import install as DistutilsInstall
-
+import sys
 import subprocess
 
+try:
+    import tensorflow
+except ImportError:
+    print("Please install tensorflow 0.12.0 or later")
+    sys.exit()
+
+
 class MyInstall(DistutilsInstall):
     def run(self):
         subprocess.call(['make', '-C', 'roi_pooling', 'build'])
@@ -19,4 +27,6 @@ def run(self):
             cmdclass={'install': MyInstall}
 )
 
+
+