Add ability to convert CSV Row objects to JSON

[vincentlaucsb]

Requirements

• Add a method to CSVRow that converts it to a valid JSON string.
  • Strings should contain minimal whitespace
  • Characters that have special meaning in JSON need to be escaped properly
  • Method should throw an error if non-Unicode characters are found
• Add unit tests for above method

For example, if there's a row with column names "Artist" and "Album" with entries "Florida Georgia Line" and "Here's To The Good Times" respectively, then the output should be

{"Artist":"Florida Georgia Line","Album":"Here's To The Good Times"}

Suggestions

We may consider using another C++ library to handle JSON serializing instead of implementing it ourselves. That library can then be added as an optional dependency, e.g. users will need to have that library to use JSON serialization. For unit tests, that library can be included under the /tests/ directory.

Suggested library: https://github.com/nlohmann/json

References

• JSON Specification: https://tools.ietf.org/html/rfc8259
• Characters to escape: https://stackoverflow.com/a/27516892/9134654