Revert "Remove Bors required test for Windows"

[curquiza]

Reverts meilisearch/milli#612

Because the issue does not seem to be there!

Closes https://github.com/meilisearch/milli/issues/614

[curquiza]

bors try

[bors[bot]]

try

Build succeeded:

• Tests on ubuntu-18.04
• Run Rustfmt
• Tests on macos-latest
• Tests on windows-latest

[bors[bot]]

Build succeeded:

• Run Rustfmt
• Tests on macos-latest
• Tests on ubuntu-18.04
• Tests on windows-latest