Bump elliptic-curve to v0.10; MSRV 1.51+ (#268)

Also updates the following:
- `p256` v0.9
- `p384` v0.8

cli/README.md

@@ -18,7 +18,7 @@ utility with general-purpose public-key encryption and signing support.
 
 ## Minimum Supported Rust Version
 
-- Rust **1.39+**
+Rust **1.51** or newer.
 
 ## Supported YubiKeys
 
@@ -47,7 +47,7 @@ For more information, please see [CODE_OF_CONDUCT.md][cc-md].
 
 ## License
 
-Copyright (c) 2014-2019 Yubico AB, Tony Arcieri
+Copyright (c) 2014-2021 Yubico AB, Tony Arcieri
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

cli/src/lib.rs

@@ -1,4 +1,4 @@
-//! `yubikey` command-line utility
+//! `yubikey` command-line utility.
 
 #![forbid(unsafe_code)]
 #![warn(
@@ -22,7 +22,7 @@ use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
 use x509_parser::parse_x509_certificate;
 use yubikey::{certificate::Certificate, key::*, YubiKey};
 
-///Write information about certificate found in slot a la yubico-piv-tool output.
+/// Write information about certificate found in slot a la yubico-piv-tool output.
 pub fn print_cert_info(
     yubikey: &mut YubiKey,
     slot: SlotId,