Fix rounding error for color hex value

[yusuke024]

Without passing the colorFloat * 0xff to the round() function first, SwiftGen will incorrectly parse 0xf8f8f8 color into 0xf7f7f7.

[djbe]

Hi @Yusuke-Onishi,

Thank you for this PR. Funny that we never noticed this.

Please add a changelog entry mentioning this change, PR, and crediting yourself. Please base yourself on the format of other changelog entries, and take care to add two spaces after the . at the end of the description.

It might be best to add an extra set of test cases for our color hex string parser, to test your specific case + some other ones. Could you write it, or do you need some help with it? (best to put it in a separate test file such as ColorParserTests.swift)

[yusuke024]

Hi @djbe , sorry for the delay.
I've updated the log file but I'm not sure how to test this one.
Since NSColor.hexValue is marked as fileprivate and @testable doesn't seem to work, I think I can only test it via ColorsCLRFileParser which basically can be done by adding more entries to the Resources/Fixtures/Colors/colors.clr file.
If you have any suggestions please let me know.

Also, when I tried to run rake it gave the below error (I have Xcode 8.3.2). I had to modify the script to make it works.

== Compile using Xcode ==
rake aborted!

[!!!] You need to have Xcode 8.x to compile SwiftGen.

/Users/st20966/Developer/SwiftGenKit/rakelib/utils.rake:73:in `version_select'
/Users/st20966/Developer/SwiftGenKit/rakelib/utils.rake:13:in `block in run'
/Users/st20966/Developer/SwiftGenKit/rakelib/utils.rake:12:in `map'
/Users/st20966/Developer/SwiftGenKit/rakelib/utils.rake:12:in `run'
/Users/st20966/Developer/SwiftGenKit/rakelib/xcode.rake:10:in `block (2 levels) in <top (required)>'
/Users/st20966/.brew/lib/ruby/gems/2.4.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
Tasks: TOP => default => xcode:test => xcode:build
(See full trace by running task with --trace)```

[djbe]

Really quick comment (will look at the testing question later), you can fix that error by doing this:
SwiftGen/StencilSwiftKit#32 (comment)

[djbe]

You can mark the method as internal. We just need tests for a couple of values, for example #000000, #FFFFFF, your color and maybe some more.