Add clean command on gulp
Add make task (clean, copy, compile, remove sources)
Rename task (use underscore)
Change path of stylesheet (fix #7)
Revert "Change path of stylesheet (fix #7)"

This reverts commit 2b2df2cbd1f67ffc3fb335113f5e6eee49fce59b.
Merge pull request #6 from kenji0919/make_gulpfile

#1 Make gulpfile