v0.4.0

[ethanbass]

chromConverter 0.4.0

New features

• Added parser for ANDI chrom cdf files through the read_cdf function.
• Added parser for 'Lumex' .mdf files through the read_mdf function.
• Added additional options for file exports. New options for writing
  chemstation_csv (utf-16) and ANDI chrom cdf files through read_chroms.
• Added preliminary support for automatic filetype detection by read_chroms when providing direct paths to files (i.e. when find_files == FALSE).
• Added read_varian_peaklist function for reading peak lists from 'Varian MS Workstation'.

Other improvements and bug fixes:

• Added wide and long data_format options for 2D data, such that the wide format option writes retention times as rownames of the matrix or data.frame. while the long format writes retention times as the first column of the object.
• Updated configure_openchrom for better discovery of 'OpenChrom' path and added path argument for directly specifying the path to 'OpenChrom'.
• Slightly restructured metadata fields. Added source_file field to track
  data origin.
• Standardized datetime stamps so they are always converted to POSIXct format.
• Now use fs package for parsing paths, eliminating buggy check_paths function.
• Fixed bug causing sloppy 'Chemstation' FID metadata.
• Fixed bug that caused padding of 'Chemstation 130' files with extra zeros.
• Added additional tests.