update tutorial

make plotting array more clear
and black and white tricks
update slides with official date and time
initial version of fitting tutorial
Merge pull request #1 from gitcheng/master

multivariate analysis
revise fitting
fix markdown
rename breitwigner to rtv_britwigner
minor text edit
show draw_profile
revise sometext
Merge pull request #6 from piti118/setup_link

revise sometext
Add a simple Decision Tree example