Uploads and attaches a file a specified issue. (Note: include the file extention when using the 'filename' option or this will change the file type.)

        Arguments:
            |   issue (string)  	| A JIRA Issue that a watcher needs added to, can be an issue ID or Key		|
            |   attachment (string) | A string pointing to a file location to upload and attach to the issue	|
            |   filename (string)  	| (Optional) A string to rename the file to upon attaching to the issue  	|

        Example:
            |  *Keyword*        		|  *Parameters* | 							         |						|
            |  connect to jira          |  asimmons     | options= {'http://devjira01'}      | 						|
            |  ${issue}					|  create issue |  ${issue_field_dict}	             |  True 			 	|
            |  add attchment to issue	|  ${issue}		|  ./logfile.text			         |  LogInformation.txt	|

def add_attachment_to_issue(self, issue, attachment, filename=None):
        """
        Uploads and attaches a file a specified issue. (Note: include the file extention when using the 'filename' option or this will change the file type.)

        Arguments:
            |   issue (string)  	| A JIRA Issue that a watcher needs added to, can be an issue ID or Key		|
            |   attachment (string) | A string pointing to a file location to upload and attach to the issue	|
            |   filename (string)  	| (Optional) A string to rename the file to upon attaching to the issue  	|

        Example:
            |  *Keyword*        		|  *Parameters* | 							         |						|
            |  connect to jira          |  asimmons     | options= {'http://devjira01'}      | 						|
            |  ${issue}					|  create issue |  ${issue_field_dict}	             |  True 			 	|
            |  add attchment to issue	|  ${issue}		|  ./logfile.text			         |  LogInformation.txt	|
        """
        self.jira.add_attachment(issue=issue, attachment=attachment,
                                 filename=filename)