changed line breaks in app.js to be more jshint friendly

Hi, First off, thanks for publishing this express-cloudant boilerplare. I'm just diving in to it, but so far so good. I love couchdb, and so far am loving cloudant. Thanks, Alex

After following the readme, and running: foreman run grunt && foreman start

I received the follow errors (see below). I realize that I probably could have run jshint using laxbreak, or maybe used "--force", but it seemed cleaner to follow the jshint convention of ending line breaks with an operator.

Running "jshint:files" (jshint) task
Linting app.js ...ERROR
[L12:C17] W014: Bad line breaking before '+'.
                + process.env.USERNAME
Linting app.js ...ERROR
[L13:C17] W014: Bad line breaking before '+'.
                + ".cloudant.com",
Linting app.js ...ERROR
[L15:C17] W014: Bad line breaking before '+'.
                + process.env.USERNAME
Linting app.js ...ERROR
[L16:C17] W014: Bad line breaking before '+'.
                + ":"
Linting app.js ...ERROR
[L17:C17] W014: Bad line breaking before '+'.
                + process.env.PASSWORD
Linting app.js ...ERROR
[L18:C17] W014: Bad line breaking before '+'.
                + "@"
Linting app.js ...ERROR
[L19:C17] W014: Bad line breaking before '+'.
                + process.env.USERNAME
Linting app.js ...ERROR
[L20:C17] W014: Bad line breaking before '+'.
                + ".cloudant.com";

Warning: Task "jshint:files" failed. Use --force to continue.

Aborted due to warnings.