Shoppers are souring on Lululemon — and the once-thriving yoga chain is meanwhile getting squeezed by new rivals.  The pricey retailer known for its $100 leggings has been discounting at “alarming rates” — even as it has been losing customers to competitors, according to new research from investment bank Jefferies.At one location ahead of the July 4 weekend, a slim-fit skirt was marked down to $49 from $78 while a pair of jogger pants were marked down to $89 from $128. 5 Lululemon was known for being sti ...