support keep spec properties order

[efi-tectonic]

This PR solves issue #125 (Keep object's parameters order as specified in swagger spec definition).

Before loading the spec , if argument--keep-spec-order exists , it will inject x-order attribute to each property which is equal to its position in the spec file.

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This change is 

[codecov]

Codecov Report

Merging #1939 into master will decrease coverage by 0.07%.
The diff coverage is 60.52%.

@@            Coverage Diff             @@
##           master    #1939      +/-   ##
==========================================
- Coverage   80.91%   80.84%   -0.08%     
==========================================
  Files          38       38              
  Lines        7589     7627      +38     
==========================================
+ Hits         6141     6166      +25     
- Misses        965      972       +7     
- Partials      483      489       +6

Impacted Files	Coverage Δ
generator/shared.go	85.38% <ø> (ø)	⬆️
cmd/swagger/commands/generate/server.go	100% <100%> (ø)	⬆️
generator/support.go	86.54% <59.45%> (-2.11%)	⬇️
generator/structs.go	75.45% <0%> (+1.81%)	⬆️

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[casualjim]

would it be possible to add a test demonstrating this behavior?

[efi-tectonic]

would it be possible to add a test demonstrating this behavior?

1. Where should I add the test?
2. Do you what to assert the generated go file ?

[casualjim]

This is used in the generation process right?
you can add the test in ./generator/model_test.go for example
I think in this case you can provide a go file with the expected result and see that the output of the render matches.

[efiko12]

Am I missing tests for codecov checks ?

[casualjim]

Codecov is always unhappy, it's not a required check

[mayurpate]

I am using mixin tool to create a single file from multiple swagger specs. In a primary/final spec, I want to maintain the properties order. This option seems to be available only for "generate server" command.

Can we make this available for mixin command as well?

[BrendanMartin]

Can this work for generate spec as well?

[terranvigil]

Can this work for generate spec as well?

It doesn't appear to but would also like to see this happen.