Business Green: Tesla has this week signed a deal with Lotus that will allow the electric car firm to continue to sell its high-profile Roadster sports car up until it begins to ship its planned Model S electric sedan. The company, which recently filed for a $100m IPO, signaled earlier this year that it would halt production of the Roadster during 2011. The move was intended to increase the firm’s focus on the development of its more affordable Model S and also served to underline the Roadster’s …