Merge pull request #885 from cuviper/indexmap-std

Explicitly enable indexmap/std

Author: dtolnay

Cargo.toml

@@ -14,7 +14,7 @@ rust-version = "1.36"
 
 [dependencies]
 serde = { version = "1.0.100", default-features = false }
-indexmap = { version = "1.5", optional = true }
+indexmap = { version = "1.5.2", features = ["std"], optional = true }
 itoa = "1.0"
 ryu = "1.0"