Remove support for the version attribute

First added in #161 this never ended up panning out, so let's remove the
experimental suport which isn't actually used by anything today and hold off on
any other changes until an RFC happens.

crates/macro-support/src/parser.rs

@@ -53,17 +53,6 @@ impl BindgenAttrs {
             .next()
     }
 
-    /// Get the first version attribute
-    fn version(&self) -> Option<&str> {
-        self.attrs
-            .iter()
-            .filter_map(|a| match a {
-                BindgenAttr::Version(s) => Some(&s[..]),
-                _ => None,
-            })
-            .next()
-    }
-
     /// Whether the catch attribute is present
     fn catch(&self) -> bool {
         self.attrs.iter().any(|a| match a {
@@ -195,7 +184,6 @@ pub enum BindgenAttr {
     StaticMethodOf(Ident),
     JsNamespace(Ident),
     Module(String),
-    Version(String),
     Getter(Option<Ident>),
     Setter(Option<Ident>),
     Structural,
@@ -257,13 +245,6 @@ impl syn::synom::Synom for BindgenAttr {
             (s.value())
         )=> { BindgenAttr::Module }
         |
-        do_parse!(
-            call!(term, "version") >>
-            punct!(=) >>
-            s: syn!(syn::LitStr) >>
-            (s.value())
-        )=> { BindgenAttr::Version }
-        |
         do_parse!(
             call!(term, "js_name") >>
             punct!(=) >>
@@ -909,10 +890,6 @@ impl<'a> MacroParse<&'a BindgenAttrs> for syn::ForeignItem {
             BindgenAttrs::find(attrs)?
         };
         let module = item_opts.module().or(opts.module()).map(|s| s.to_string());
-        let version = item_opts
-            .version()
-            .or(opts.version())
-            .map(|s| s.to_string());
         let js_namespace = item_opts.js_namespace().or(opts.js_namespace()).cloned();
         let kind = match self {
             syn::ForeignItem::Fn(f) => f.convert((item_opts, &module))?,
@@ -923,7 +900,6 @@ impl<'a> MacroParse<&'a BindgenAttrs> for syn::ForeignItem {
 
         program.imports.push(ast::Import {
             module,
-            version,
             js_namespace,
             kind,
         });