0.4

What's Changed

• improve date & datetime handling by @JanMarvin in #18
• Provide tests by @JanMarvin in #23
• select column or row by @JanMarvin in #24
• Skipahead by @JanMarvin in #25
• use std::vector not Rcpp::Vector by @JanMarvin in #26
• reduce in Rcpp function by @JanMarvin in #28
• provide conversion to time by @JanMarvin in #27
• import "" as NA_character_ by @JanMarvin in #30
• bump version by @JanMarvin in #31

Full Changelog: 0.2...0.4