removed human_task_ibfk_5 from old migration file and updated task id removal migration to work with both mysql and postgres w/ burnettk

spiffworkflow-backend/migrations/versions/0c7428378d6e_.py

@@ -446,7 +446,7 @@ def upgrade():
     sa.ForeignKeyConstraint(['completed_by_user_id'], ['user.id'], ),
     sa.ForeignKeyConstraint(['lane_assignment_id'], ['group.id'], ),
     sa.ForeignKeyConstraint(['process_instance_id'], ['process_instance.id'], ),
-    sa.ForeignKeyConstraint(['task_model_id'], ['task.id'], name='human_task_ibfk_5'),
+    sa.ForeignKeyConstraint(['task_model_id'], ['task.id']),
     sa.PrimaryKeyConstraint('id')
     )
     with op.batch_alter_table('human_task', schema=None) as batch_op:

spiffworkflow-backend/migrations/versions/3191627ae224_.py

@@ -20,6 +20,9 @@ depends_on = None
 def is_mysql() -> bool:
    return dialect_name() == 'mysql' 
 
+def is_postgres() -> bool:
+   return dialect_name() == 'postgres' 
+
 
 def upgrade():
     # ### commands auto generated by Alembic - please adjust! ###
@@ -31,7 +34,12 @@ def upgrade():
 
     with op.batch_alter_table('human_task', schema=None) as batch_op:
         batch_op.add_column(sa.Column('task_guid', sa.String(length=36), nullable=True))
-        batch_op.drop_constraint('human_task_ibfk_5', type_='foreignkey')
+
+        # sqlite does not seem to have this foreignkey constraint
+        if is_postgres():
+            batch_op.drop_constraint('human_task_task_model_id_fkey', type_='foreignkey')
+        elif is_mysql():
+            batch_op.drop_constraint('human_task_ibfk_5', type_='foreignkey')
         batch_op.drop_index('ix_human_task_task_model_id')
         batch_op.create_index(batch_op.f('ix_human_task_task_guid'), ['task_guid'], unique=False)
         batch_op.create_foreign_key('human_task_ibfk_task_guid', 'task', ['task_guid'], ['guid'])