Update docs for :help tests.

tests/integration/features/misc.feature

@@ -194,7 +194,8 @@ Feature: Various utility commands.
         Then the error "Invalid help topic foo!" should be shown
 
     Scenario: :help with command
-        When I run :tab-only
+        When the documentation is up to date
+        And I run :tab-only
         And I run :help :back
         And I wait until qute://help/commands.html#back is loaded
         Then the following tabs should be open:
@@ -205,7 +206,8 @@ Feature: Various utility commands.
         Then the error "Invalid command foo!" should be shown
 
     Scenario: :help with setting
-        When I run :tab-only
+        When the documentation is up to date
+        And I run :tab-only
         And I run :help general->editor
         And I wait until qute://help/settings.html#general-editor is loaded
         Then the following tabs should be open:

tests/integration/features/test_misc.py

@@ -17,5 +17,33 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
+import os.path
+import subprocess
+
+import pytest
 import pytest_bdd as bdd
 bdd.scenarios('misc.feature')
+
+import qutebrowser
+from qutebrowser.utils import docutils
+
+
+@bdd.when("the documentation is up to date")
+def update_documentation():
+    """Update the docs before testing :help."""
+    base_path = os.path.dirname(os.path.abspath(qutebrowser.__file__))
+    doc_path = os.path.join(base_path, 'html', 'doc')
+    script_path = os.path.join(base_path, '..', 'scripts')
+
+    if all(docutils.docs_up_to_date(path) for path in os.listdir(doc_path)):
+        return
+
+    try:
+        subprocess.call(['asciidoc'], stdout=subprocess.DEVNULL,
+                        stderr=subprocess.DEVNULL)
+    except OSError:
+        pytest.skip("Docs outdated and asciidoc unavailable!")
+
+    update_script = os.path.join(script_path, 'asciidoc2html.py')
+    subprocess.call([sys.executable, update_script])