Adding support for reading CSV files.

[vote539]

I added support for reading CSV files. This will provide better support for users who want to use this module with the option of the alternative spreadsheet format. The changes are as follows:

1. Added dependencies on mime for detecting file type and csv-parse for parsing CSV files.
2. Added a test case to ensure that row-oriented.xlsx parses to the same JSON as row-oriented.csv.
3. Replaced the row-oriented.csv failure test case with a GIF file.

[coveralls]

Coverage remained the same at 100.0% when pulling 0c680ac on vote539:csv-support into 3830613 on stevetarver:master.

[codecov-io]

Current coverage is 100% (diff: 100%)

Merging #4 into master will not change coverage

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  Lines          78   116    +38   
  Methods         1     1          
  Messages        0     0          
  Branches       17    21     +4   
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+ Hits           78   116    +38   
  Misses          0     0          
  Partials        0     0          

Powered by Codecov. Last update 3830613...1e76897

[coveralls]

Coverage decreased (-14.05%) to 85.95% when pulling afa253d on vote539:csv-support into 3830613 on stevetarver:master.

[vote539]

In addition to the basic CSV support, I added a synchronous API to my branch (including tests and documentation). Note that since the dependency "excel" does not expose a synchronous API, right now the synchronous API does not support XLSX files.

[coveralls]

Coverage decreased (-0.9%) to 99.138% when pulling 14e7bdd on vote539:csv-support into 3830613 on stevetarver:master.

[coveralls]

Coverage decreased (-0.9%) to 99.138% when pulling 2609450 on vote539:csv-support into 3830613 on stevetarver:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 1e76897 on vote539:csv-support into 3830613 on stevetarver:master.

[vote539]

FYI, for the time being I have made my changes available via the npm package "@vote539/excel-as-json"