csv-parser

Fix for failing to parse leading and trailing escaped quotes (#158)

* added test showing the result of writing a value made of a leading and trailing double quotes

Test was already passing. No fix required to make it pass.

* test showing a failure when parsing leading and trailing escaped double quote

* fix to make test "Test leading and trailing escaped quote" pass

* updated single header to include fix for that makes test "Test leading and trailing escaped quote" pass