updated .travis.yml for #120
Changed attachXPublicKey to public

Added log messages for attaching invalid sub public keys
Removed unneeded QblEncPublicKey and QblSignPublicKey from Contact

These two are part of the primary public key
Added additional log messages to CryptoUtils decryptHybrid...
Changed the return type of DropHTTP receiveMessages to Collection<byte[]>

DropHTTP was sending out byte arrays but parsed received messages as
strings. This was modifiying the messages which results in the invalid
signature.

The DropTest is also modified. Class variables has been replaced with
methods variable, to avoid unintended behaviour when different tests are
using the same variables.

Also retrieveTest() is not an own JUnit test anymore, because these are
called in undefined order. Instead, this function is now called from the
send tests.

Since the keys are generated random for each run, we only expect one
drop message do be decryptable. Older messages were created with
different keys.
Merge pull request #126 from jan-schreib/travis-update

updated .travis.yml for #120
Merge pull request #125 from L-Henke/invalidSignaturesFix

Invalid signatures fix
* changed collections in config container classes to final
* collections will be instantiated while container class instatiation.
* implemented add() method in config container classes
* changed call of add() method in using classes
* modified getter methods in config container classes to return unmodifiable collections in order to prevent direct write access to them
remove @ignore anotiation from tests
made http teste working on empty redis databases

needed some additions in the @before part

this adds to #127
new class:
* QblPrimaryKeyPairTypeAdapter
new class:
* QblKeySerializationTest
-> test is not working yet as there is missing a proper equals() method for QblPrimaryKeyPair
Fixed parsing of multipart by using parseHeadless

HttpURLConnection's InputStream does not include HTTP header data.
Therefore, the mime stream parser couldn't use the content type
information transported in the content type http header field.

By using parseHeadless instead of parse, the mime parser gets the
content type info by parameter and not from the input stream itself.
fixed MultiPartCryptoTest test
Merge pull request #134 from cburkert/fix_mimestream_multipart_parsing

Fixed parsing of multipart by using parseHeadless
Merge pull request #127 from jan-schreib/unignore-tests

Un-ignore almost all tests
changed content type to application/octet-stream

closes #133
Merge pull request #136 from jan-schreib/http-content-type

changed content type to application/octet-stream