Enforce use of HTTPS with TLS >= 1.2 for curl calls (#117)
Enforce use of HTTPS with TLS >= 1.2 for curl calls (#117)

This is a follow-on to https://github.com/pantsbuild/setup/issues/116,
tightening up the security of the `curl` calls made in the `pants`
script.

I also took the liberty of replacing single-character options with
their long option equivalents for readability


jsirois/setup,pantsbuild/setup,pantsbuild/setup,jsirois/setup,jsirois/setup,pantsbuild/setup