add contributions to readme
Removing last memory warnings on buildbot (could not reproduce them locally).
minor fix
Merge pull request #2237 from yorkerlin/yorker-integration

minor fix for Integration.cpp
Merge pull request #2229 from pickle27/develop

add contributions to readme
CART added
Merge pull request #2239 from mazumdarparijat/CART

CART added
added obtain_from_generic method
Merge pull request #2242 from karlnapf/develop

added CANOVAKernel::obtain_from_generic
Merge pull request #2232 from tklein23/more_valgrind_suppressions

Removing last memory warnings on buildbot (could not reproduce them locally)