Update pip version during CircleCI setup stage to resolve Rust compiler build error (as suggested in https://cryptography.io/en/latest/faq.html#installing-cryptography-fails-with-error-can-not-find-rust-compiler)
Update pip version during CircleCI setup stage to resolve Rust compiler build error (as suggested in https://cryptography.io/en/latest/faq.html#installing-cryptography-fails-with-error-can-not-find-rust-compiler)