Remove doxia dependency.

This fixes issue #6.
[maven-release-plugin] prepare release jscep-2.0.2
[maven-release-plugin] prepare for next development iteration
Added release script.
#110 - SCEP Client doesn't allow a different TransportFactory to be supplied
Merge pull request #11 from karldmoore/master

#11 - SCEP Client doesn't allow a different TransportFactory to be supplied
Use the constant instead of string literal.