Update: modernize to rust 1.65 (#337)

* Update: modernize to rust 1.65

* use workspace cargo dependencies to ensure crate/meta consistency
* update libraries and calls
* include `-A dead_code` to clippy to get around `future_state_machine`
* modern fmt/clippy recommendations
* update Docker
* Add local overrides to contract test script for local testing
* remove unused crates

.circleci/config.yml

@@ -85,9 +85,12 @@ jobs:
             cargo build
       - run:
           name: Check formatting
+          # Rust 1.65+ is stricter about dead_code and flags auto-generated methods created by
+          # state_machine_future. Since these are auto-generated, it's not possible to tag them as
+          # allowed. Adding `-A dead_code` until state_machine_future is removed.
           command: |
             cargo fmt -- --check
-            cargo clippy --all --all-targets --all-features -- -D warnings --deny=clippy::dbg_macro
+            cargo clippy --all --all-targets --all-features -- -D warnings --deny=clippy::dbg_macro -A dead_code
       - run:
           name: Integration tests
           command: py.test -v