identify parser should handle set of data, fix https://github.com/mceach...

should fix https://github.com/mceachen/micro_magick/issues/3

the difference in output, before above, after below:
```
:properties=>{:date=>"modify: 2014-09-09T19:54:01-04:00"
:properties=>{:date=>["create: 2014-09-09T19:54:28-04:00", "modify: 2014-09-09T19:54:28-04:00"]
:exif=>"YResolution: 720000/10000"
:exif=>["Artist: David Riecks", "ColorSpace: 1", "Compression: 6", "Copyright: Copyright 2003, David Riecks, all rights reserved.", "DateTime: 2009:05:27 01:08:51", "ExifImageLength: 187", "ExifImageWidth: 275", "ExifOffset: 376", "ImageDescription: After digging the furrows another ten yards with the tractor, Jim hops off to hand-set more leeks and onions.", "JPEGInterchangeFormat: 514", "JPEGInterchangeFormatLength: 4509", "Orientation: 1", "ResolutionUnit: 2", "Software: Adobe Photoshop CS3 Macintosh", "XResolution: 720000/10000", "YResolution: 720000/10000"]
:icc=>"model: IEC 61966-2.1 Default RGB colour space - sRGB"
:icc=>["copyright: Copyright (c) 1998 Hewlett-Packard Company", "description: sRGB IEC61966-2.1", "manufacturer: IEC http://www.iec.ch", "model: IEC 61966-2.1 Default RGB colour space - sRGB"]
:jpeg=>"sampling-factor: 1x1,1x1,1x1"
:jpeg=>["colorspace: 2", "sampling-factor: 1x1,1x1,1x1"]
:profiles=>{:profile_iptc=>{:keyword_2_25_=>"Leeks"
:profiles=>{:profile_iptc=>{:keyword_2_25_=>["white", "outdoors", "vegetables", "male", "caucasian", "outside", "horizontal", "Person", "plants", "Agriculture", "Crops", "tractor", "outdoor", "conceptual", "organic", "farmer", "concept", "agronomy", "crop", "concepts", "abundance", "repetition", "granger", "farmhand", "farm hand", "field hand", "farm laborer", "field worker", "human", "human being", "human beings", "humans", "white person", "masculine", "30-55 years old", "onions", "vegetable crops", "agricultural equipment", "horizontals", "able-bodied", "farm fresh", "sustainable agriculture", "organic farming", "organics", "Leeks"]
:pixels_per_second=>"5.143MB"
:pixels_per_second=>"0B"
:elapsed_time=>"0:01.009"
:elapsed_time=>"0:01.000"
```

while this certainly doesn't give 100% usage for all the values, it does not break anything, and fixes the iptc keywords.
```
results[:profiles][:profile_iptc][:keyword_2_25_]
 => ["white", "outdoors", "vegetables", "male", "caucasian", "outside", "horizontal", "Person", "plants", "Agriculture", "Crops", "tractor", "outdoor", "conceptual", "organic", "farmer", "concept", "agronomy", "crop", "concepts", "abundance", "repetition", "granger", "farmhand", "farm hand", "field hand", "farm laborer", "field worker", "human", "human being", "human beings", "humans", "white person", "masculine", "30-55 years old", "onions", "vegetable crops", "agricultural equipment", "horizontals", "able-bodied", "farm fresh", "sustainable agriculture", "organic farming", "organics", "Leeks"]
```