add test_popupdate.py

We had no coverage over aurweb.scripts.popupdate. This test covers
all of its functionality.
Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/db.py

+import math
+
 try:
     import mysql.connector
 except ImportError:
@@ -91,6 +93,7 @@ class Connection:
         elif aur_db_backend == 'sqlite':
             aur_db_name = aurweb.config.get('database', 'name')
             self._conn = sqlite3.connect(aur_db_name)
+            self._conn.create_function("POWER", 2, math.pow)
             self._paramstyle = sqlite3.paramstyle
         else:
             raise ValueError('unsupported database backend')

aurweb/scripts/popupdate.py

@@ -7,7 +7,6 @@ import aurweb.db
 
 def main():
     conn = aurweb.db.Connection()
-
     conn.execute("UPDATE PackageBases SET NumVotes = (" +
                  "SELECT COUNT(*) FROM PackageVotes " +
                  "WHERE PackageVotes.PackageBaseID = PackageBases.ID)")

test/test_popupdate.py

+from aurweb.scripts import popupdate
+
+
+def test_popupdate():
+    popupdate.main()