More idiomatic patching of the MCP23S17 dependency.

Cargo.toml

@@ -20,15 +20,13 @@ resolver = "2"
 
 [dependencies]
 log = "0.4.17"
-# rppal-mcp23s17 = { path = "../rppal-mcp23s17" }
-rppal-mcp23s17 = { version = "0.1" }
+rppal-mcp23s17 = "0.1"
 rppal = "0.19.0"
 thiserror = "1.0.37"
 
 [dev-dependencies]
 anyhow = "1.0.66"
 env_logger = "0.11.3"
-# rppal-mcp23s17 = { path = "../rppal-mcp23s17", features = ["mockspi"] }
 rppal-mcp23s17 = { features = ["mockspi"], version = "0.1" }
 
 [features]
@@ -37,3 +35,7 @@ rppal-mcp23s17 = { features = ["mockspi"], version = "0.1" }
 # SPI which is suited to running tests without needing the target Raspberry Pi
 # hardware. Also requires the rppal_mcp23s17 crate to support the mock SPI.
 mockspi = ["rppal-mcp23s17/mockspi"]
+
+# Uncomment when testing against a locally modified version of the MCP23S17 dependency.
+[patch.crates-io]
+# rppal-mcp23s17 = { path = "../rppal-mcp23s17" }