Rebuild on changes to SOURCE_DATE_EPOCH

#65

support two function: git_clean(),git_status_file()

0.6.8

update README.md

Make embedded timestamps timezone independent

#64

fix time format without timezone

#63 #61

add SOURCE_DATE_EPOCH value support

fix #61

0.6.4

fix git2 crates 0.13.18 build error by rust version 1.54.0

0.6.3

#57

0.6.2

#56

0.6.1.1

Update README.md

update doc

0.6.1

Update Cargo.toml