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/monero/ringct/bulletproofs/src/tests/plus/mod.rs

@@ -0,0 +1,4 @@
+#[cfg(test)]
+mod weighted_inner_product;
+#[cfg(test)]
+mod aggregate_range_proof;