issue-503: added type map in example value

[Arrim]

Describe the PR
Add example tag for maps

Relation issue
#503

Additional context
Example:

type MyStruct struct {
   MyMap map[string]string 'json:"my_map" swaggertype:"map,string" example:"key1:value1,key2:value2"'
 }

[sdghchj]

1. Swagger have no real map or dictionary type, so it use object type with additionalProperties alternatively. And also, schemaType have no chance to be "map" in your PR. You can test it.
2. I found swagger editor doesn't support example for object type. You can confirm it.

[Arrim]

@sdghchj This type is needed to form an example json request with an arbitrary data set. For instance:
{
"data": {
"myKey1": "myData1",
"myKey2": "myData2",
"myKey3": "myData3",
}
}
I know that maybe this is a design error, but sometimes it is necessary. At the moment, swag is not able to generate such data.
And yes, I checked with my example - it works.

[sdghchj]

@Arrim Can you show your exmaple result?

[codecov-commenter]

Codecov Report

Merging #683 (30b0f37) into master (09f9621) will increase coverage by 1.06%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #683      +/-   ##
==========================================
+ Coverage   82.64%   83.70%   +1.06%     
==========================================
  Files           8        8              
  Lines        1642     1663      +21     
==========================================
+ Hits         1357     1392      +35     
+ Misses        168      160       -8     
+ Partials      117      111       -6     

Impacted Files	Coverage Δ
parser.go	79.60% <100.00%> (+0.86%)	⬆️
schema.go	98.71% <100.00%> (+14.21%)	⬆️

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[rogaha]

any updates here?

[Arrim]

Hi. Sorry for the delay. I updated my code.
Swagger really not support map type. But map type in go is an object in swagger(JSON).
I use object type for a map and check child type in the "defineTypeOfExample" method. If child type not set returned error. And if the child typeset and correct, I add an example in documentation.

I add an example code in the repository, where you may check the correct result.

[Arrim]

@sdghchj @easonlin404 Hi. You can merge pr?

[sdghchj]

LGTM