Allows more that one space between css selector.

This is needed to support addToken_ workaround before the fix.
Before the fix, an extra space was needed in the selector like this

example:

    addToken "form.foo "

With the fix adding the missing space, code already adding a space
will end up with two spaces between the scope selector and the input one :

    form.foo  input[name=token_]

yesod-test/Yesod/Test/CssQuery.hs

@@ -51,7 +51,7 @@ parseQuery = parseOnly cssQuery
 
 -- Below this line is the Parsec parser for css queries.
 cssQuery :: Parser [[SelectorGroup]]
-cssQuery = many (char ' ') >> sepBy rules (char ',' >> optional (char ' '))
+cssQuery = many (char ' ') >> sepBy rules (char ',' >> many (char ' '))
 
 rules :: Parser [SelectorGroup]
 rules = many $ directChildren <|> deepChildren
@@ -102,4 +102,4 @@ pSquare :: Parser a -> Parser a
 pSquare p = char '[' *> p <* char ']'
 
 pOptionalTrailingSpace :: Parser a -> Parser a
-pOptionalTrailingSpace p = p <* optional (char ' ')
+pOptionalTrailingSpace p = p <* many (char ' ')