Add restlet maven repository in pom.xml, Remove openjdk8 in .travis.yml

	Restlet libraries are not present in the maven
central repository so it is necessary to add external
repository such as maven.restlet.com.

	There is no support for openjdk8 in travis, so
it is removed temporarily and we will find ways to port
this library in openjdk8.

 Changes committed:
	modified:   .travis.yml
	modified:   pom.xml
Merging github repo updates