add explicit call to coveralls binary

tox.ini

@@ -3,10 +3,14 @@ minversion = 1.3
 envlist = py26,py27,docs,flake8
 
 [testenv]
-deps=nose 
-     coveralls 
-     coverage
-commands=nosetests --with-coverage --cover-package=wstools
+deps=
+    nose 
+    coveralls 
+    coverage
+commands=
+    nosetests --with-coverage --cover-package=wstools
+    bash -c "coveralls || true"
+whitelist_externals=bash
 
 [testenv:py26]