Update to bashate 0.4.0

Update to bashate 0.4.0.  The biggest change in this is that bashate
does a syntax check with "bash -n" which can be useful

Change-Id: Iff625ef2181dfaba28349dc17de0749faddec539
diff --git a/tox.ini b/tox.ini
index f9d04f2..efffbd5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,7 +9,7 @@
 
 [testenv:bashate]
 deps =
-   {env:BASHATE_INSTALL_PATH:bashate==0.3.2}
+   {env:BASHATE_INSTALL_PATH:bashate==0.4.0}
 whitelist_externals = bash
 commands = bash -c "find {toxinidir}             \
          -not \( -type d -name .?\* -prune \)    \