Update unused Python 3.5 references

Dockerfile

@@ -1,16 +1,15 @@
-FROM ubuntu:18.04
-
-MAINTAINER Marco Chiappetta <[email protected]>
+FROM ubuntu:latest
 
 # Needed to be able to install python versions.
 RUN apt-get update && apt-get install -y software-properties-common
 RUN add-apt-repository ppa:deadsnakes/ppa
 
 RUN apt-get update && apt-get install -y \
-	python3.5 \
 	python3.6 \
 	python3.7 \
 	python3.8 \
+	python3.9 \
+	python3.10 \
 	gdal-bin \
 	python3-pip
 

setup.py

@@ -27,7 +27,7 @@
     author='hipo',
     author_email='[email protected]',
     url='https://github.com/Hipo/drf-extra-fields',
-    python_requires=">=3.5",
+    python_requires=">3.6",
     install_requires=requirements,
     classifiers=[
         'Environment :: Web Environment',
@@ -37,7 +37,6 @@
         'License :: OSI Approved :: BSD License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',

tox.ini

@@ -1,6 +1,5 @@
 [gh-actions]
 python =
-    3.5: py35
     3.6: py36
     3.7: py37
     3.8: py38