Move the list of optional python packages into setup.py, and have dh_python3...

Move the list of optional python packages into setup.py, and have dh_python3 check the generated requires.txt

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

debian/rules

@@ -46,17 +46,9 @@ override_dh_auto_build: debian/diffoscope.bash-completion
 
 override_dh_python3:
 	dh_python3 -p diffoscope \
-		--depends=distro \
-		--recommends=argcomplete \
-		--recommends=binwalk \
-		--recommends=defusedxml \
-		--recommends=guestfs \
-		--recommends=jsondiff \
-		--recommends=progressbar \
-		--recommends=python-debian \
-		--recommends=pyxattr \
-		--recommends=rpm-python \
-		--recommends=tlsh \
+		--depends-section=distro_detection \
+		--recommends-section=cmdline \
+		--recommends-section=comparators \
 
 override_dh_gencontrol:
 	bin/diffoscope --list-debian-substvars >> debian/diffoscope.substvars

setup.py

@@ -54,6 +54,17 @@ setup(
     ],
     extras_require={
         'distro_detection': ['distro'],
+        'cmdline': ['argcomplete', 'progressbar'],
+        'comparators': [
+            'binwalk',
+            'defusedxml',
+            'guestfs',
+            'jsondiff',
+            'python-debian',
+            'pyxattr',
+            'rpm-python',
+            'tlsh',
+        ],
     },
     classifiers=[
         'Development Status :: 3 - Alpha',