#77 achieve 100% test coverage for indicators - linregint
#77 achieve 100% test coverage for indicators - linregslp
#77 achieve 100% test coverage for indicators - llv
#77 achieve 100% test coverage for indicators - llvbars
#77 achieve 100% test coverage for indicators - macd
#77 achieve 100% test coverage for indicators - medianprice
#77 achieve 100% test coverage for indicators - mfi