Through death, depression and diabetes Haim just keep getting stronger. With that difficult second album out the way – and an even more difficult couple of years personally behind them – the Cali sisters are back with a load of new tunes, a ripped-up rule book and a determination to do things their way. Charlotte Gunn meets the band in LA and finds that if you’re going to throw Haim lemons, you better get ready for a whole lot of lemonade.