Added small changes to find sage in system.

Author: mmasdeu

.travis-test.sh

@@ -1,9 +1,10 @@
-#! /bin/sh
+#! /bin/bash
 # Copying and distribution of this file, with or without modification,
 # are permitted in any medium without royalty provided the copyright
 # notice and this notice are preserved.  This file is offered as-is,
 # without any warranty.
 set -e
+export PATH=$PATH:$HOME/SageMath
 $HOME/SageMath/sage -pip install --upgrade -i https://pypi.python.org/pypi -v sagemath
 $HOME/SageMath/sage -pip install --upgrade --no-index -v .
 $HOME/SageMath/sage setup.py test

setup.py

@@ -30,7 +30,10 @@ def readfile(filename):
 # Check the right Sage version
 class build(build_module.build):
     def run(self):
-        errno = os.system('''sage -python -c "from sagemath.check_version import check_version; check_version('%s')"'''%sage_required_version)
+        try:
+            errno = os.system('''sage -python -c "from sagemath.check_version import check_version; check_version('%s')"'''%sage_required_version)
+        except ValueError:
+            errno = -1
         if errno != 0:
             sys.exit(1)
         # from sagemath.check_version import check_version