fix the path separator is a backslash on windows

[yishui01]

Describe what this PR does / why we need it

Windows用jupiter脚手架在go.mod的多层子级目录下创建new demo时，import的路径会带有windows路径的反斜杠
比如 go.mod 在最外层，同级有一个目录为 A, 在windows的A/B/C里的C目录 下创建new demo时生成的代码import路径出错

Does this pull request fix one issue?

None

Describe how you did it

jupiter new demo

Describe how to verify it

Special notes for reviews

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 25.04%. Comparing base (36b1f98) to head (465c375).
⚠️ Report is 680 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #192      +/-   ##
==========================================
- Coverage   26.14%   25.04%   -1.11%     
==========================================
  Files          77       77              
  Lines        4566     3837     -729     
==========================================
- Hits         1194      961     -233     
+ Misses       3257     2764     -493     
+ Partials      115      112       -3     

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