Added pacman invalid option rule (#960)

* Added pacman invalid option rule

* Added test

* flake8 fixes

* Test changes

* Test fix

* Typo - again

* Travis test fix

* More Travis

* Even more travis

* I hope im right here

* Update README.md

Co-Authored-By: Pablo Aguiar <scorphus@gmail.com>

* Update thefuck/rules/pacman_invalid_option.py

Co-Authored-By: Pablo Aguiar <scorphus@gmail.com>

Co-authored-by: Pablo Aguiar <scorphus@gmail.com>

tests/rules/test_pacman_invalid_option.py

@@ -0,0 +1,21 @@
+from thefuck.rules.pacman_invalid_option import get_new_command, match
+from thefuck.types import Command
+
+good_output = "community/shared_meataxe 1.0-3\n    A set of programs for working with matrix representations over finite fields\n    "
+
+bad_output = "error: invalid option '-s'"
+
+
+def test_match():
+    assert not match(Command('pacman -Ss meat', good_output))
+    assert not match(Command('sudo pacman -Ss meat', good_output))
+    assert match(Command('pacman -ss meat', bad_output))
+    assert match(Command('sudo pacman -ss meat', bad_output))
+
+
+def test_get_new_command():
+    new_command = get_new_command(Command('pacman -ss meat', bad_output))
+    assert new_command == 'pacman -Ss meat'
+
+    new_command = get_new_command(Command('sudo pacman -s meat', bad_output))
+    assert new_command == 'sudo pacman -S meat'