Made DropSerializer test working.

Forgot how to use embedded classes...
remove unneeded imports
Added log4j 2.+ to build.gradle
Merge pull request #47 from jan-schreib/dropserializer-test-fix

Made DropSerializer test working.
combined symm dec and enc test
added .travis.yml

closes #13
Merge pull request #57 from jan-schreib/travis

added .travis.yml
trigger travis.
added travis picture
Merge pull request #56 from roeslpa/basicSymmetricEncryption

combined symm dec and enc test
Merge pull request #54 from L-Henke/log4j

Added log4j 2.+ to build.gradle
Added signature to encrypted messages.
Changed visibilities of methods in CryptoUtils.
Added log messages for (currently) unhandled exceptions.
Fixed usage of wrong RSAPrivateKey in CryptoUtils rsaSign()
Fixed sub-key signing. Changed method named in CryptoUtils
Fixed CryptoUtils rsa sign fix again
Changed CryptoUtils logger to final static
Merge pull request #59 from L-Henke/cryptoImprovement

Added signature to encrypted messages and CryptoUtils improvement.
Added Bouncy Castle cryptographic provider to build.gradle
Switched cryptographic provider to Bouncy Castle
Switched RSA signing algorithm to RSASSA-PSS
Merge pull request #63 from L-Henke/bouncyCastle

Added Bouncy Castle cryptographic provider to build.gradle
Changed rsaSign() parameter name from 'message' to 'data' to avoid confusion