Add Emscripten build in Travis

test_suite/tests/test_de.rs

@@ -156,8 +156,12 @@ macro_rules! declare_tests {
         )+
     };
 
-    ($($name:ident { $($value:expr => $tokens:expr,)+ })+) => {
+    ($(
+        $(#[$cfg:meta])*
+        $name:ident { $($value:expr => $tokens:expr,)+ }
+    )+) => {
         $(
+            $(#[$cfg])*
             #[test]
             fn $name() {
                 $(
@@ -260,6 +264,7 @@ declare_tests! {
         0f32 => &[Token::F32(0.)],
         0f64 => &[Token::F64(0.)],
     }
+    #[cfg(not(target_arch = "wasm32"))]
     test_small_int_to_128 {
         1i128 => &[Token::I8(1)],
         1i128 => &[Token::I16(1)],