Fix a few issues with initial setup.
Fix a few issues with initial setup.

 - Always apply shimmering width.
 - Update default shimmering width.
 - Set duration properly for fade. (#12)

takeshineshiro/Shimmer,Kevin775263419/Shimmer,ernestopino/Shimmer,iOSTestApps/Shimmer,zdiovo/Shimmer,gank0326/shimmer,HarrisLee/Shimmer,moneytree/Shimmer,xb123456456/Shimmer,AlanJN/Shimmer,liuzechen/Shimmer,tuanpa199/Shimmer,yang7229693/Shimmer,SuPair/Shimmer,suchitabohra/Shimmer,bangslosan/Shimmer,1yvT0s/Shimmer,toughie88/Shimmer,godLoveLucifer/Shimmer,Suninus/Shimmer,iOS--wsl--victor/Shimmer,freebird999/Shimmer,kingloveyy/Shimmer,dinhchitrung/Shimmer