Add Lets Encrypt to JDK keystore

Will probably need to do this on more client machines:

wget https://letsencrypt.org/certs/isrgrootx1.pem
wget https://letsencrypt.org/certs/letsencryptauthorityx1.der

sudo keytool -trustcacerts -keystore /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/jre/lib/security/cacerts -storepass changeit -noprompt -importcert -alias isrgrootx1 -file ~/Downloads/isrgrootx1.pem
sudo keytool -trustcacerts -keystore /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/jre/lib/security/cacerts -storepass changeit -noprompt -importcert -alias letsencryptauthorityx1 -file ~/Downloads/letsencryptauthorityx1.der