[All] Prep. & clean-up leading to 4.3.x changes

* Updated deps (incl. HTTParty & rOCCI-core)
* Cleaned up old PKCS12 stuff
* Updated gem description & mail addresses
* Added HTTP 202 Accepted to valid server responses
Updated Travis-CI integration
Merge pull request #12 from arax/prep_for_4_3_x

[All] Prep. & clean-up leading to 4.3.x changes