Bump JWT core to 1.87.0 for Cognito token support

[Duslerke]

What:

• Update the Hackney.Core.JWT package multiple versions up (1.49 -> ... -> 1.87).

Why:

• To get the latest version of the ITokenFactory implementation that adds support for the Cognito token schema.

Notes:

• The versions in between have no consequence. The only thing that changed about Token schema is Nbf, Exp, and Iat field types being changed from int to long.
• What changes does latest (v1.87.0) JWT intoduce? See PR: Add cognito authentication flow token schema support. lbh-core#68.
• These changes do not require immediate deployment, they merely need to be present within the repo's main branch. This is so those changes would already be there for when anyone would introduce new changes attempting to access Google groups from the token. Without this JWT version bump, any attempted access of Groups within the token would make the API wouldn't fall over.