Fix typo.

Author: gilesgas

jenkins/scripts/test.sh

@@ -7,7 +7,7 @@ echo 'https://docs.npmjs.com/cli/install, the "--save-dev" flag causes the'
 echo '"cross-env" dependency to be installed as "devDependencies". For the'
 echo 'purposes of this tutorial, this flag is not important. However, when'
 echo 'installing this dependency, it would typically be done so using this'
-echo 'flag. For a comprehensive exaplanation about "devDependencies", see'
+echo 'flag. For a comprehensive explanation about "devDependencies", see'
 echo 'https://stackoverflow.com/questions/18875674/whats-the-difference-between-dependencies-devdependencies-and-peerdependencies.'
 set -x
 # npm install --save-dev cross-env