Replace remaining python2.4 shebang lines.
Fixes #40.
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index a5f2541..de2e6b2 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2014 Google Inc. All Rights Reserved.
diff --git a/tests/test_errors.py b/tests/test_errors.py
index 3a3c3fd..efb4afd 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All Rights Reserved.
#
diff --git a/tests/test_http.py b/tests/test_http.py
index b4bf007..e8a3580 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All Rights Reserved.
#
diff --git a/tests/test_json_model.py b/tests/test_json_model.py
index fccd549..c8a985b 100644
--- a/tests/test_json_model.py
+++ b/tests/test_json_model.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All Rights Reserved.
#
diff --git a/tests/test_mocks.py b/tests/test_mocks.py
index 7d1e8e6..4d9fd80 100644
--- a/tests/test_mocks.py
+++ b/tests/test_mocks.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All Rights Reserved.
#
diff --git a/tests/test_model.py b/tests/test_model.py
index 6bc87be..9f29db9 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
# -*- coding:utf-8 -*-
#
# Copyright 2014 Google Inc. All Rights Reserved.
diff --git a/tests/test_protobuf_model.py b/tests/test_protobuf_model.py
index 02544e1..fe3abc7 100644
--- a/tests/test_protobuf_model.py
+++ b/tests/test_protobuf_model.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All Rights Reserved.
#