use theano.__file__ in mpi_test

One of the mpi tests needs to run a file in the theano file system. It is now pointed to that file through the theano.__file__ attribute.

use theano.file in mpi_test
4db5662f · Matthew Rocklin · 234f7460 · 4db5662f
--- a/theano/tensor/tests/test_mpi.py
+++ b/theano/tensor/tests/test_mpi.py
@@ -38,8 +38,9 @@ def test_mpi_roundtrip():
 #    assert p.stdout.read() == "True"
    if not mpi_enabled:
        return
-    sin, sout, serr = os.popen3("mpiexec -np 2 python "
-                                "theano/tensor/tests/_test_mpi_roundtrip.py")
+    theano_root = theano.__file__.split('__init__')[0]
+    sin, sout, serr = os.popen3("mpiexec -np 2 python " + theano_root +
+                                "tensor/tests/_test_mpi_roundtrip.py")
    result = sout.read()
    assert "True" in result