Backslash character parser bugs in NTriples parser

[robstewart57]

let Right (g::RDF TList) =
    parseString
         NTriplesParser
         (Data.Text.pack "<http://a.example/s> <http://a.example/p> \"\\r\" .")

Evaluating g:

Triple (UNode "http://a.example/s") (UNode "http://a.example/p") (LNode (PlainL "r"))

So the \r character is being parsed just as r.

This is the reason for a number of TurtleParser tests failing, since their results are compared against NTriple golden references parsed with the NTriples parser, e.g.

• stack test --test-arguments="--pattern literal_with_escaped_CARRIAGE_RETURN"
• stack test --test-arguments="--pattern literal_with_CHARACTER_TABULATION"

[wismill]

Hi, this is fixed in #55