Fix for @JsonProperty annotation

The same change as described in #440 but to develop branch:


1. Annotation from field are not read when @JsonProperty annotation is on getter, because it take name from annotation on getter and search for wrong field name.

Current model of parsing annotation on Model class is as follow:
- Read annotations from getter, if there is @JsonProperty replace getter name with value of annotation
- Read annotation from field. Field name is resolved from getter name or wrongly taken from value of @JsonProperty if it existed on getter,

Example:

```
@JsonProperty("access_token")
public String getAccessToken() {
 return accessToken;
}
```

It is try to find property with name access_token not accessToken.

2. It is not possible to use annotation @JsonProperty on field, only on method, because name from getter is resolved in first place:

```
@JsonProperty("access_token")
@ApiModelProperty(value = "The access token.", required = true)
private String accessToken;
```

I add patch which solve both problems.