Fix some spelling mistakes

tests/rules/test_mercurial.py

@@ -2,7 +2,7 @@ import pytest
 
 from tests.utils import Command
 from thefuck.rules.mercurial import (
-    extract_possisiblities, match, get_new_command
+    extract_possibilities, match, get_new_command
 )
 
 
@@ -96,8 +96,8 @@ def test_not_match(command):
         '\n    rebase recover remove rename resolve revert'
     )), ['rebase', 'recover', 'remove', 'rename', 'resolve', 'revert']),
 ])
-def test_extract_possisiblities(command, possibilities):
-    assert extract_possisiblities(command) == possibilities
+def test_extract_possibilities(command, possibilities):
+    assert extract_possibilities(command) == possibilities
 
 
 @pytest.mark.parametrize('command, new_command', [

thefuck/rules/dirty_untar.py

@@ -13,12 +13,12 @@ def _is_tar_extract(cmd):
 
 
 def _tar_file(cmd):
-    tar_extentions = ('.tar', '.tar.Z', '.tar.bz2', '.tar.gz', '.tar.lz',
+    tar_extensions = ('.tar', '.tar.Z', '.tar.bz2', '.tar.gz', '.tar.lz',
                       '.tar.lzma', '.tar.xz', '.taz', '.tb2', '.tbz', '.tbz2',
                       '.tgz', '.tlz', '.txz', '.tz')
 
     for c in cmd.split():
-        for ext in tar_extentions:
+        for ext in tar_extensions:
             if c.endswith(ext):
                 return (c, c[0:len(c)-len(ext)])
 

thefuck/rules/mercurial.py

@@ -2,7 +2,7 @@ import re
 from thefuck.utils import get_closest
 
 
-def extract_possisiblities(command):
+def extract_possibilities(command):
     possib = re.findall(r'\n\(did you mean one of ([^\?]+)\?\)', command.stderr)
     if possib:
         return possib[0].split(', ')
@@ -24,6 +24,6 @@ def match(command, settings):
 
 def get_new_command(command, settings):
     script = command.script.split(' ')
-    possisiblities = extract_possisiblities(command)
-    script[1] = get_closest(script[1], possisiblities)
+    possibilities = extract_possibilities(command)
+    script[1] = get_closest(script[1], possibilities)
     return ' '.join(script)