converted "exit(0)" to "sys.exit(0)" in some test files.

modules/bindings/tests/test_blast.py

@@ -43,8 +43,8 @@ if __name__ == "__main__":
     blastpath=settings.Locate('blastall')
   except(settings.FileNotFound):
     print "Could not find blastall executable: ignoring unit tests"
-    exit(0)
+    sys.exit(0)
   try:
     unittest.main()
   except Exception, e:
-    print e
\ No newline at end of file
+    print e

modules/bindings/tests/test_clustalw.py

@@ -67,8 +67,8 @@ if __name__ == "__main__":
     clustalw_path=settings.Locate(('clustalw', 'clustalw2'))
   except(settings.FileNotFound):
     print "Could not find clustalw executable: ignoring unit tests"
-    exit(0)
+    sys.exit(0)
   try:
     unittest.main()
   except Exception, e:
-    print e
\ No newline at end of file
+    print e

modules/seq/alg/tests/test_renumber.py

@@ -117,8 +117,8 @@ if __name__ == "__main__":
     clustalw_path=settings.Locate(('clustalw', 'clustalw2'))
   except(settings.FileNotFound):
     print "Could not find clustalw executable: ignoring unit tests"
-    exit(0)  
+    sys.exit(0)  
   try:
     unittest.main()
   except Exception, e:
-    print e
\ No newline at end of file
+    print e