* Add new optional way to create CodePush instance based on builder pattern
Add constructor with additional option PublicKeyFilePath
* Adapt changes from old code-signing branch
Add `com.auth0:java-jwt:3.2.0` to deps
Adapt changes from code-signing branch
Fix errors appeared due to jwt library update.
* Non-breaking change of CodePush constructor, downgrade jwt library
Replace publicKey by publicKeyResourceDescriptor in CodePush constructor
Downgrade jwt library to 2.2.2 due to issue with base64 decoding
* Make code signing optional
* Add small improvements
Replace CodePushUnknownException catch with
CodePushInvalidPublicKeyException in certain places
Make mPublicKey static
Add additional log for applying updates
* Rename method verifyJWT with verifyAndDecodeJWT
* Add minor fixes
Add additional checking for potential problems with code-signing
integration
Fix Public Key parsing from strings.xml
* Fix constructors
* Fix constructors bug
* Fix log messages