Add libgmime-2.6-dev to ubuntu-trusty; resolves travis-ci/apt-package-whitelist#3895
Add libgmime-2.6-dev to ubuntu-trusty; resolves travis-ci/apt-package-whitelist#3895

Packages: libgmime-2.6-dev libgmime-2.6-doc libgmime-2.6-0 gmime-bin libgmime-2.6-0-dbg libgmime2.6-cil libgmime2.6-cil-dev monodoc-gmime2.6-manual

travis-ci/apt-package-whitelist,travis-ci/apt-package-whitelist