add-user: fix function header

Problem: When the max_jobs column was added to the flux-accounting DB
in flux-framework#131, it was not added to the function declaration of add_user(),
resulting in a NOT NULL constraint failure when attempting to add a
user. This error gets raised when calling the add-user subcommand
in flux-account.py.

Solution: Add max_jobs to the function header of add_user() and
to the SQL statement of a user when being added to the flux-accounting
DB.

src/bindings/python/fluxacct/accounting/user_subcommands.py

@@ -45,6 +45,7 @@ def add_user(
     uid=65534,
     admin_level=1,
     shares=1,
+    max_jobs=5,
 ):
 
     # get uid of user
@@ -83,9 +84,10 @@ def add_user(
                 admin_level,
                 bank,
                 default_bank,
-                shares
+                shares,
+                max_jobs
             )
-            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
             """,
             (
                 int(time.time()),
@@ -97,6 +99,7 @@ def add_user(
                 bank,
                 default_bank,
                 shares,
+                max_jobs,
             ),
         )
         # commit changes