Local attestation - App written in Rust

There are a bunch of function that I need from
```
extern crate sgx_tstd as std;
```

within the enclaves.

Adding it as a dependency to the Cargo file of each enclave causes a dependency clash. How can I use the common attestation dependency so that I only import these functions once?

e.g error:

```
error: cannot find macro `println` in this scope
--> src/lib.rs:33:5
|
33 | println!("testing that this gets imported");
```

Start by reviewing the Cargo file for each enclave and the `extern crate sgx_tstd as std;` usage, then inspect `src/lib.rs` at the failing `println!` call. Determine whether the shared attestation dependency can provide the needed functions without a dependency clash; done means the enclave code compiles and the macro is available.

Written by the indexing model from the issue text.