Fix weekly tick labels in Python quickstart

docs/_docs/quick_start.md

@@ -148,36 +148,36 @@ forecast[['ds', 'yhat', 'yhat_lower', 'yhat_upper']].tail()
       <th>3265</th>
       <td>2017-01-15</td>
       <td>8.205065</td>
-      <td>7.480528</td>
-      <td>8.889085</td>
+      <td>7.518780</td>
+      <td>8.899184</td>
     </tr>
     <tr>
       <th>3266</th>
       <td>2017-01-16</td>
       <td>8.530088</td>
-      <td>7.805730</td>
-      <td>9.296309</td>
+      <td>7.752344</td>
+      <td>9.246332</td>
     </tr>
     <tr>
       <th>3267</th>
       <td>2017-01-17</td>
       <td>8.317468</td>
-      <td>7.576534</td>
-      <td>9.060808</td>
+      <td>7.641099</td>
+      <td>9.039998</td>
     </tr>
     <tr>
       <th>3268</th>
       <td>2017-01-18</td>
       <td>8.150081</td>
-      <td>7.440242</td>
-      <td>8.906296</td>
+      <td>7.333512</td>
+      <td>8.888837</td>
     </tr>
     <tr>
       <th>3269</th>
       <td>2017-01-19</td>
       <td>8.162015</td>
-      <td>7.433653</td>
-      <td>8.902665</td>
+      <td>7.415570</td>
+      <td>8.850360</td>
     </tr>
   </tbody>
 </table>
@@ -254,12 +254,12 @@ tail(forecast[c('ds', 'yhat', 'yhat_lower', 'yhat_upper')])
 ```
 
                  ds     yhat yhat_lower yhat_upper
-    3264 2017-01-13 8.052054   7.332958   8.698754
-    3265 2017-01-14 7.832396   7.077789   8.578120
-    3266 2017-01-15 8.214232   7.397416   8.922169
-    3267 2017-01-16 8.539239   7.786306   9.239885
-    3268 2017-01-17 8.326654   7.562416   9.042217
-    3269 2017-01-18 8.159337   7.449771   8.869469
+    3264 2017-01-13 8.052054   7.328934   8.845277
+    3265 2017-01-14 7.832396   7.147092   8.515437
+    3266 2017-01-15 8.214232   7.439343   8.947970
+    3267 2017-01-16 8.539239   7.804152   9.243396
+    3268 2017-01-17 8.326654   7.635376   9.036896
+    3269 2017-01-18 8.159337   7.445167   8.907354