Show build status for master branch
Show build status for master branch

By default the badges show the build status for the most recent build,
which could be a pull request or experimental branch.  The one we want
to display in the README is the most recent for master.

Signed-off-by: Kevin Locke <ffb4761cba839470133bee36aeb139f58d7dbaa9@kevinlocke.name>

kevinoid/travis-status,kevinoid/node-project-template,kevinoid/stream-compare,kevinoid/swagger-spec-validator,kevinoid/appveyor-status,kevinoid/promised-read,kevinoid/swagger-spec-validator,kevinoid/promised-read,kevinoid/travis-status,kevinoid/git-branch-is,kevinoid/swagger-spec-validator,kevinoid/node-project-template,kevinoid/appveyor-status,kevinoid/node-project-template,kevinoid/stream-compare,kevinoid/travis-status,kevinoid/promised-read,kevinoid/stream-compare,kevinoid/git-branch-is,kevinoid/appveyor-status,kevinoid/git-branch-is