Update to upstream version 0.0.62

Detailed maintainer log:

• v0.0.62: Miscellaneous tweaks
• Updated Let's Encrypt agreement URL in example response file.
• Now builds for current Go 1.x version in Travis rather than Go 1.8.
• More error details are now available for challenge errors in the acmeapi package.
• Error when trying to prompt the user in non-interactive mode now advises user to remove --batch flag.

PR: 224627
Submitted by: samm@os2.kiev.ua (maintainer)
MFH: 2018Q1