fix(abigen): abigen feature required for bindings (#1508)

* fix(abigen): abigen feature required for bindings

traits such as ethers::contract::EthDisplay require abigen

* update changelog

* abigen now uses re-exported version of serde_json

CHANGELOG.md

@@ -97,6 +97,8 @@
   [#1498](https://github.com/gakonst/ethers-rs/pull/1498). Note: this changes
   generated module names to snake case. For example, `MyContract` is now
   `my_contract` rather than `mycontract_mod`.
+- The `Cargo.toml` generated by bindings now includes the `abigen` feature on
+  ethers. [#1508](https://github.com/gakonst/ethers-rs/pull/1508)
 
 ### 0.6.0
 

ethers-contract/ethers-contract-abigen/src/multi.rs

@@ -530,8 +530,7 @@ impl MultiBindingsInner {
         writeln!(
             toml,
             r#"
-ethers = {{ git = "https://github.com/gakonst/ethers-rs", default-features = false }}
-serde_json = "1.0.79"
+ethers = {{ git = "https://github.com/gakonst/ethers-rs", default-features = false, features = ["abigen"] }}
 "#
         )?;
         Ok(toml)