switch to OAuth auth. method

app.py

@@ -19,7 +19,6 @@ def get_nearest_image(lat, lon, radius=50):
     Get the nearest Mapillary image to given coordinates
     """
     params = {
-        'access_token': MAPILLARY_ACCESS_TOKEN,
         'fields': 'id,thumb_1024_url',
         'limit': 1
     }
@@ -31,11 +30,13 @@ def get_nearest_image(lat, lon, radius=50):
     }}
     """
     
+    header = {'Authorization' : 'OAuth {}'.format(MAPILLARY_ACCESS_TOKEN)}
     try:
         response = requests.post(
             "https://graph.mapillary.com/images/search",
             json=query,
-            params=params
+            params=params,
+            headers=header
         )
         response.raise_for_status()
         data = response.json()