Add apt_upgrade rule (#761)

* apt_list_upgradable: Prepend sudo to suggestion if used in command

* Add apt_upgrade rule

This suggests `apt upgrade` after `apt list --upgradable` if there are
packages to upgrade. It pairs well with the `apt_list_upgradable` rule,
which suggests `apt list --upgradable` after `apt update` if there are
packages to upgrade.

* Add apt_upgrade rule to README

tests/rules/test_apt_upgrade.py

@@ -0,0 +1,36 @@
+import pytest
+from thefuck.rules.apt_upgrade import get_new_command, match
+from thefuck.types import Command
+
+match_output = '''
+Listing... Done
+heroku/stable 6.15.2-1 amd64 [upgradable from: 6.14.43-1]
+resolvconf/zesty-updates,zesty-updates 1.79ubuntu4.1 all [upgradable from: 1.79ubuntu4]
+squashfs-tools/zesty-updates 1:4.3-3ubuntu2.17.04.1 amd64 [upgradable from: 1:4.3-3ubuntu2]
+unattended-upgrades/zesty-updates,zesty-updates 0.93.1ubuntu2.4 all [upgradable from: 0.93.1ubuntu2.3]
+'''
+
+no_match_output = '''
+Listing... Done
+'''
+
+
+def test_match():
+    assert match(Command('apt list --upgradable', match_output))
+    assert match(Command('sudo apt list --upgradable', match_output))
+
+
+@pytest.mark.parametrize('command', [
+    Command('apt list --upgradable', no_match_output),
+    Command('sudo apt list --upgradable', no_match_output)
+])
+def test_not_match(command):
+    assert not match(command)
+
+
+def test_get_new_command():
+    new_command = get_new_command(Command('apt list --upgradable', match_output))
+    assert new_command == 'apt upgrade'
+
+    new_command = get_new_command(Command('sudo apt list --upgradable', match_output))
+    assert new_command == 'sudo apt upgrade'