Update call to scipy.linalg.eigh to not use deprecated eigvals parameter (#210)

Co-authored-by: Blair Bonnett <blair.bonnett@hsu-hh.de>

[skip ci]

Author: bcbnz

requirements.txt

@@ -1,3 +1,3 @@
 numpy>=1.13
-scipy>=0.18.0
+scipy>=1.5.0
 numba>=0.49.1

src/quaternion/__init__.py

@@ -353,15 +353,15 @@ def from_rotation_matrix(rot, nonorthogonal=True):
 
         if not shape:
             q = zero.copy()
-            eigvals, eigvecs = linalg.eigh(K3.T, eigvals=(3, 3))
+            eigvals, eigvecs = linalg.eigh(K3.T, subset_by_index=(3, 3))
             q.components[0] = eigvecs[-1]
             q.components[1:] = -eigvecs[:-1].flatten()
             return q
         else:
             q = np.empty(shape+(4,), dtype=np.float64)
             for flat_index in range(reduce(mul, shape)):
                 multi_index = np.unravel_index(flat_index, shape)
-                eigvals, eigvecs = linalg.eigh(K3[multi_index], eigvals=(3, 3))
+                eigvals, eigvecs = linalg.eigh(K3[multi_index], subset_by_index=(3, 3))
                 q[multi_index+(0,)] = eigvecs[-1]
                 q[multi_index+(slice(1,None),)] = -eigvecs[:-1].flatten()
             return as_quat_array(q)