Rename bang->apply

! syntax item has been referred to as "bang" instead of "apply" in some
places, this is fixed

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/syn/parser.rs

@@ -117,7 +117,7 @@ impl<'t> Parser<'t> {
 
     pub fn next_atom(&mut self) -> Result<SpAtom> {
         use Token::*;
-        let token = self.expect_any_token(&[Assign, Word, Float, Int, Str, Bang])?;
+        let token = self.expect_any_token(&[Assign, Word, Float, Int, Str, Apply])?;
         Ok(self.token_to_atom(token))
     }
 
@@ -131,7 +131,7 @@ impl<'t> Parser<'t> {
             Token::Float => Atom::Float(text.parse().unwrap()),
             Token::Int => Atom::Int(text.parse().unwrap()),
             Token::Str => Atom::Str(unescape_string(text)),
-            Token::Bang => Atom::Apply,
+            Token::Apply => Atom::Apply,
             _ => panic!("invalid token specified for token_to_atom, it should be an atom"),
         };
         SpAtom::new(span, atom)