Updated README with specific information about how to get gini.net pu…

…blic key hash.

Issue #60

README.md

@@ -74,8 +74,14 @@ GiniSDK *sdk = [[GINISDKBuilder anonymousUserWithClientID:@"your_client_id"
                                    publicKeyPinningConfig:trustKitConfig] build];
 ```
 
+If `kTSKEnforcePinning` is set to `false`, any SSL connection will be block even if the pinning fails. When it is enabled, it requires at least two hashes (the second one is a backup hash).
 When using `TrustKit` some messages are shown in the console log. It is possible to either specify a custom log for messages or disable it altogether (setting it as nil). To do so just use the `TrustKit.setLoggerBlock` method before initializing the `trustKitConfig`.
 
+The Gini API public key SHA256 hash in Base64 encoding can be extracted with the following `openssl` commands:
+```bash
+openssl s_client -servername gini.net -connect gini.net:443 | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64
+```
+
 ## Requirements
 - iOS 8.0+
 - Xcode 8.0+