fix: Calculate-distance/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-DJANGO-2329158
- https://snyk.io/vuln/SNYK-PYTHON-DJANGO-2329159
- https://snyk.io/vuln/SNYK-PYTHON-DJANGO-2329160

Author: snyk-bot

Calculate-distance/requirements.txt

@@ -1,4 +1,4 @@
 geopy==2.1.0
 folium==0.12.1
 django-crispy-forms==1.11.0
-Django==3.1.14
+Django==2.2.26