Here's how I solved it. Based on http://askubuntu.com/a/683947 and http://stackoverflow.com/a/34916570
Download cUrl from http://curl.haxx.se/download.html
Then in your terminal, run these commands
$ tar -xzf curl-***.tar.gz
$ cd curl-*.*.*
$ ./configure --with---with-darwinssl
$ make
$ sudo make install
cURL should now have https support!
$ curl -V
curl 7.49.1 (x86_64-apple-darwin15.4.0) libcurl/7.49.1 OpenSSL/1.0.2h zlib/1.2.8
Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP UnixSockets