remove unused dependencies and in-repo included js libraries

.gitignore

@@ -1,2 +1,4 @@
 *.json
-web/assets/leaflet.*
+web/assets/leaflet*
+web/assets/moment*
+web/assets/chart*

preparedata.py

@@ -1,6 +1,6 @@
 #!/usr/bin/python3
 
-import os, re, json, demjson, datetime, urllib.request
+import os, re, json, datetime, urllib.request
 
 # you can obtain the county-centres-bavaria.json file by running the following
 #  query on overpass-turbo.eu and export the result as GeoJSON
@@ -81,5 +81,8 @@
 with open("web/history/{}.json".format(timestamp), "w+", encoding="utf-8") as fd:
     json.dump(bavariaData, fd, indent=4)
 
-os.unlink("web/data.json")
+try:
+    os.unlink("web/data.json")
+except:
+    pass
 os.symlink("history/{}.json".format(timestamp), "web/data.json")

web/graph.html

@@ -30,8 +30,10 @@
 
 		<canvas></canvas>
 
-		<script src="assets/moment.min.js"></script>
-		<script src="assets/Chart.min.js"></script>
+		<!-- e.g. https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.3/moment.min.js -->
+		<script src="assets/moment-2.29.3.js"></script>
+		<!-- e.g. https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.bundle.min.js -->
+		<script src="assets/chart-2.9.3.js"></script>
 		<script src="assets/graph.js"></script>
 	</body>
 </html>

web/index.html

@@ -21,7 +21,8 @@
         <meta property="twitter:image" content="https://corona.bayern/assets/bayern-corona.png" />
         <meta property="twitter:title" content="Corona in Bayern" />
 
-        <link rel="stylesheet" href="assets/leaflet.css" />
+        <!-- e.g. https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.4/leaflet.css -->
+        <link rel="stylesheet" href="assets/leaflet-1.3.4.css" />
 
         <style>
             #info {
@@ -113,8 +114,8 @@
             <a href="/graph.html">Historie</a>
         </div>
 
-        <script src="assets/leaflet.js"></script>
-        <script src="assets/semicircle.js"></script>
+        <!-- e.g. https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.4/leaflet.js -->
+        <script src="assets/leaflet-1.3.4.js"></script>
         <script src="assets/script.js"></script>
     </body>
 </html>