Add newline characters between each line when viewing logs as text

[olivierbellone]

When viewing logs as text (e.g. https://botbot.me/freenode/stripe/2016-05-22.log), no newline characters are inserted between each line. This makes it needlessly hard to parse the logs.

This PR fixes the template used for the text view to append a newline character after each line.

[ipmb]

Thanks @olivierbellone!