fix: JWT Security Warning

[yasirfolio3]

Summary

• Updating JWT library from https://github.com/dgrijalva/jwt-go to https://github.com/golang-jwt/jwt because of security issues since the former one is no longer maintained and it is suggested to move to the later one.
• Updating to version [v3.2.1](https://github.com/golang-jwt/jwt/releases/tag/v3.2.1) of the library since post this version, only go version 1.15 and upwards are supported whereas agent uses go 1.13.

Issues

• GHSA-w73w-5m7g-f7qc

GO Release Policy

• Each major Go release is supported until there are two newer major releases. For example, Go 1.5 was supported until the Go 1.7 release, and Go 1.6 was supported until the Go 1.8 release. We fix critical problems, including critical security problems, in supported releases as needed by issuing minor revisions (for example, Go 1.6.1, Go 1.6.2, and so on).

[msohailhussain]

lgtm