Rename the coins folder to networks (#583)

* Rename the coins folder to networks

Ethereum isn't a coin. It's a network.

Resolves #357.

* More renames of coins -> networks in orchestration

* Correct paths in tests/

* cargo fmt

networks/bitcoin/src/lib.rs

@@ -0,0 +1,24 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+
+/// The bitcoin Rust library.
+pub use bitcoin;
+
+/// Cryptographic helpers.
+#[cfg(feature = "hazmat")]
+pub mod crypto;
+#[cfg(not(feature = "hazmat"))]
+pub(crate) mod crypto;
+
+/// Wallet functionality to create transactions.
+pub mod wallet;
+/// A minimal asynchronous Bitcoin RPC client.
+#[cfg(feature = "std")]
+pub mod rpc;
+
+#[cfg(test)]
+mod tests;