tests: move to root directory

tests/test_sampling.py

@@ -0,0 +1,17 @@
+import sampling
+import numpy as np
+
+
+def test_resample():
+    x = np.arange(300)
+    s = sampling.Sampler(x)
+    y = np.array(list(s))
+
+    err = x[1:len(y)+1] - y
+    assert np.max(np.abs(err)) < 1e-10
+
+
+def test_coeffs():
+    I = sampling.Interpolator(width=4, resolution=16)
+    err = I.filt[0] - [0, 0, 0, 1, 0, 0, 0, 0]
+    assert np.max(np.abs(err)) < 1e-10