Add a number of fixes to the IOS data parser

[JessyBarrette]

Add a number of changes to the IOS data parser to bring it closer to the original format generated the cioos-siooc-data-transform package and used by IOS.

See #82 #81 #74 for the list of changes.

guanlu129 You can test the latest version of the changes made here by uninstalling and reinstalling on your own machine the ocean-data-parser via the following command:

• if package is already installed remove it with

  pip uninstall ocean_data_parser

• Install latest version of the fix-74-dfo-ios-update branch version

  pip install git+https://github.com/cioos-siooc/ocean-data-parser.git@fix-74-dfo-ios-update

What's left?

• [ ] confirm all issues are fulfilled in #82 #81 #74
• [ ] seawater* variables handling #83
• [ ] platform_depth
• [ ] test changes with IOS full datasets
• [ ] Add reference NetCDF files to track changes associated to output to IOS ios_shell parser to NetCDFs