Add libpetsc3.6.2-dev to ubuntu-precise; resolves travis-ci/apt-package-whitelist#1535
Add libpetsc3.6.2-dev to ubuntu-precise; resolves travis-ci/apt-package-whitelist#1535

Packages: libpetsc3.6.2-dev petsc-dev libpetsc3.6 libpetsc3.6.2-dbg petsc3.6.2-doc libpetsc-complex-3.6.2-dev libpetsc-complex-3.6 libpetsc-complex-3.6.2-dbg

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