Failure to parse

I tried adding this macro to this enum: https://github.com/apollographql/apollo-cli/blob/920b15820f1847af97732d15da9c1436a8ddd3c3/cli/src/cli.rs#L54-L65

I received this error message:
```
= help: message: should parse input tokens into AST: "failed to parse derive input: \"pub enum Subcommand {\\n\\n #[structopt(name = \\\"update\\\")]\\n /// 🚀 update the Apollo CLI\\n Update(commands::Update),\\n\\n #[structopt(name = \\\"print\\\", setting = AppSettings :: Hidden)]\\n /// 🖨 parse and pretty print schemas to stdout\\n Print(commands::Print),\\n\\n #[structopt(name = \\\"setup\\\", setting = AppSettings :: Hidden)]\\n /// 🚜 setup the Apollo toolchain in your environment\\n Setup(commands::Setup),\\n}\""
```

added using
`#[derive(derive_is_enum_variant::is_enum_variant)]`