Fix clippy lints and update packages (#568)

# Conflicts:
#	Cargo.lock

graphene/src/layers/layer_info.rs

@@ -186,7 +186,7 @@ impl Layer {
 		match &self.data {
 			LayerDataType::Shape(s) => Ok(&s.style),
 			LayerDataType::Text(t) => Ok(&t.style),
-			_ => return Err(DocumentError::NotAShape),
+			_ => Err(DocumentError::NotAShape),
 		}
 	}
 
@@ -194,7 +194,7 @@ impl Layer {
 		match &mut self.data {
 			LayerDataType::Shape(s) => Ok(&mut s.style),
 			LayerDataType::Text(t) => Ok(&mut t.style),
-			_ => return Err(DocumentError::NotAShape),
+			_ => Err(DocumentError::NotAShape),
 		}
 	}
 }

graphene/src/layers/shape_layer.rs

@@ -192,9 +192,9 @@ impl ShapeLayer {
 			// Solve with Thomas algorithm (see https://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm)
 			for i in 1..n {
 				let m = a[i] / b[i - 1];
-				// TODO: Fix Clippy warning which makes the borrow checker angry
-				b[i] = b[i] - m * c[i - 1];
-				r[i] = r[i] - m * r[i - 1];
+				b[i] -= m * c[i - 1];
+				let last_iteration_r = r[i - 1];
+				r[i] -= m * last_iteration_r;
 			}
 
 			// Determine first control point for each segment