Update bootstrap dependency versions

[chenriksson]

Should fix https://github.com/NuGet/Engineering/issues/1565

Recommended updates, per https://github.com/NuGet/NuGetGallery/network/dependencies

• fresh, 0.5.0 (recommend >= 0.5.2)
• mime, 1.3.4 (recommend >= 1.4.1)
• no-case, 2.3.1 (recommend >= 2.3.2)
• tough-cookie, 2.3.2 (recommend >= 2.3.3)

Applied updates with the following commands, from .\src\Bootstrap (npm version 6.1.0). Note that there were no changes to the generated files under .\dist

npm install [email protected]
npm install [email protected]
npm install [email protected]
npm install [email protected]
rm .\dist\css\*
rm .\dist\js\*.js
grunt