fix typo

navipy/moving/agent.py

@@ -393,7 +393,7 @@ the agent motion, or
                            timeout=1,
                            filename=None,
                            blocksize=100):
-        if os.path.exist(filename):
+        if os.path.exists(filename):
             self.velocities = pd.read_hdf()
         nodes_tocompute = self.velocities.isna().any(axis=1)
         nodes_tocompute = nodes_tocompute[nodes_tocompute].index