Update index.md

Reference to the latest OASIS API version.

Author: elec7reify

public/content/developers/docs/programming-languages/rust/index.md

@@ -42,7 +42,7 @@ Need a more basic primer first? Check out [ethereum.org/learn](/learn/) or [ethe
 - [pwasm-ethereum](https://github.com/paritytech/pwasm-ethereum) - _Collection of externs to interact with ethereum-like network_
 - [Lighthouse](https://github.com/sigp/lighthouse) - _Fast Ethereum consensus layer client_
 - [Ethereum WebAssembly](https://ewasm.readthedocs.io/en/mkdocs/) - _Proposed redesign of the Ethereum smart contract execution layer using a deterministic subset of WebAssembly_
-- [oasis_std](https://docs.rs/oasis-std/0.2.7/oasis_std/) - _OASIS API reference_
+- [oasis_std](https://docs.rs/oasis-std/latest/oasis_std/index.html) - _OASIS API reference_
 - [Solaris](https://github.com/paritytech/sol-rs) - _Solidity Smart Contracts unit test harness using the native Parity Client EVM._
 - [SputnikVM](https://github.com/rust-blockchain/evm) - _Rust Ethereum Virtual Machine Implementation_
 - [Wavelet](https://wavelet.perlin.net/docs/smart-contracts) - _Wavelet smart contract in Rust_