[boost] [boost-ci] code coverage build fix

For folks using boost-ci integration, here is a fix to your .travis.yml file to enable code coverage builds to work again. I received confirmation from Travis CI that a back-end update on their end corrected some security issues which necessitates this change. https://github.com/boostorg/rational/pull/22/files In the script section of the coverage job, replace the commands: cd lcov && sudo make install with: export PATH=/tmp/lcov/bin:$PATH Thanks, Jim