Add shebangs

cosine.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 def cosine_sim(known_point, new_point):
     from math import sqrt
     up, d1, d2 = 0.0, 0.0, 0.0

otsuka.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 # $K = \frac{|A \cap B|}{\sqrt{|A| \times |B|}}$
 def otsuka_sim(known_point, new_point):
     from math import sqrt