Update task.md
Merge pull request #31 from yan9yu/patch-1

Update task.md
Revert "Update task.md"

This reverts commit a9124bf36f77dfeb3ecbc89e99aa942f074c719c.
删除其他章节
half of chap9 completed
chp 10
Merge branch 'gh-pages' of https://github.com/johnstart/data-science into gh-pages
half completed.
chp14 ripe's work complete
Merge pull request #32 from ripeconan/develop

chp14 ripe's work complete
completed
finally complete
Merge pull request #33 from flymark2010/develop

chp9 completed.
Revert "chp9 completed."
Merge pull request #34 from johnstart/revert-33-develop

Revert "chp9 completed."
commit again
Merge pull request #35 from flymark2010/develop

chp9重新提交。
Merge pull request #1 from johnstart/gh-pages

merg into my fork
chp10 complete
chp10 add new pic