This one pops in a while, and despite being quite easy to do. This howto will generate the certificate and install it on your iOS simulators.
openssl genrsa -aes256 -passout pass:x -out server.pass.key 2048
openssl rsa -passin pass:x -in server.pass.key -out server.key
rm server.pass.key
openssl req -new -sha256 -key server.key -out server.csr -subj /CN=localhost
openssl x509 -req -sha512 -days 365 -in server.csr -signkey server.key -out server.crt
Clone https://github.com/ADVTOOLS/ADVTrustStore.git run it: ./iosCertTrustManager.py -a server.crt