v0.2.7

• Updates the execution handler to update final orders ensuring an execution order is created in the event of a single submission without a further rebalance.
• Updates rebalance_buy_and_hold to check if the start_dt is a business day
  If start_dt is a business day rebalance_dates = [start_dt]
  If start_dt is a weekend rebalance_dates = [next business day]
• Adds a unit test to check that the buisness day calculation is correct
• Adds an integration test to check that a backtest using buy_and_hold_rebalance generates execution orders on the correct dates