Update travisci.rst (#1200)
Update travisci.rst (#1200)

Add "the". Capitalize proper noun, "MacOS". Change tense of "installs". Change commas to parenthesis. Change awkward sentence phrasing. Fix run-on sentence. Change "too" to "also". Change "it finish" to "it has finished".
conan-io/docs,conan-io/docs,conan-io/docs,conan-io/docs