Gem search should default to lower case naming convention

[etagwerker]

Current

When I enter a gem name like "madmin" the application returns what I'm looking for:

When I enter a gem name like "Madmin" the application returns an unexpected response:

Expected

I'd expect "Madmin" to redirect to "madmin" or "MaDmIn" to redirect to "madmin"

[etagwerker]

@trusche Thanks for your PR! I can see that it is now working even if it's capitalized: https://www.railsbump.org/gems/Madmin vs. https://www.railsbump.org/gems/madmin