Adds support for template yml files in docstring

[s1113950]

Fixes #39

This converts any included yml file into a template that then gets included in docstrings if not overridden by what's already in the docstring.

It assumes for lists of dicts (like in the case of multiple parameters values) that the dicts are unique by their name attribute, in accordance with the swagger specs.

Any comments are welcome!

The new put doc:

"put": {
        "description": "<br/>",
        "parameters": [
          {
            "description": "filename. this overrides what's in the .yml file",
            "in": "formData",
            "name": "filename",
            "required": false,
            "type": "string"
          },
          {
            "description": "username",
            "in": "formData",
            "name": "username",
            "required": false,
            "type": "file"
          },
          {
            "description": "password",
            "in": "formData",
            "name": "password",
            "required": false,
            "type": "file"
          },
          {
            "in": "body",
            "name": "body",
            "schema": {
              "$ref": "#/definitions/User"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "this description stays"
          },
          "204": {
            "description": "User updated"
          }
        },
        "summary": "Update a user, this summary stays",
        "tags": [
          "user_update"
        ]
      }

The merge function is kinda complicated so I added a bunch of comments throughout explaining how the merging happens!

Also sorry about the weird branch name, messed that up accidentally 😛

[s1113950]

This is ready for review for whoever wants to check it out 😄