Fix clippy and enable clippy on CI

src/dynamics/joint/generic_joint.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::bad_bit_mask)] // Clippy will complain about the bitmasks due to JointAxesMask::FREE_FIXED_AXES being 0.
+
 use crate::dynamics::solver::MotorParameters;
 use crate::dynamics::{FixedJoint, MotorModel, PrismaticJoint, RevoluteJoint, RopeJoint};
 use crate::math::{Isometry, Point, Real, Rotation, UnitVector, Vector, SPATIAL_DIM};
@@ -704,8 +706,8 @@ impl GenericJointBuilder {
     }
 }
 
-impl Into<GenericJoint> for GenericJointBuilder {
-    fn into(self) -> GenericJoint {
-        self.0
+impl From<GenericJointBuilder> for GenericJoint {
+    fn from(val: GenericJointBuilder) -> GenericJoint {
+        val.0
     }
 }