Newlines are not possible to be encoded

[def-]

Newlines in the message of a junit_report::TestCase::failure() are stored in the XML as straight newlines. When parsing the XML (for example with python-junit-xml) they are automatically stripped. Instead the newline should be encoded as 
.

As a workaround I tried &error.to_string().replace("\n", "
"), but the 
 is then encoded as 


[bachp]

@def- Could you provide a test case that failes?

[def-]

Sure: #68