Key length is 64 for dependencies resolved via maven/jcenter

[rahul-a]

https://github.com/JakeWharton/DiskLruCache/blob/3e016356cfc7e5f9644a7a732fe0223e9742e024/src/main/java/com/jakewharton/disklrucache/DiskLruCache.java#L95

I came across an exception where my key length exceeded 64 characters, so I was browsing through the repo to figure out a reason for this cap on key length. It seems after the key length was increased, the newer jar never got deployed to maven/bintray.

[ncruces]

See #95.