package.json: add testling dev dependency + config
package.json: add testling dev dependency + config

shotishu/zxcvbn,fo0nikens/zxcvbn,signalnine/zxcvbn,fo0nikens/zxcvbn,signalnine/zxcvbn,varenc/zxcvbn,hn3000/zxcvbn,hnq90/zxcvbn,fo0nikens/zxcvbn,alextekartik/zxcvbn,shotishu/zxcvbn,shotishu/zxcvbn,varenc/zxcvbn,alextekartik/zxcvbn,paulballesty/zxcvbn,hnq90/zxcvbn,hnq90/zxcvbn,alextekartik/zxcvbn,varenc/zxcvbn,signalnine/zxcvbn,dropbox/zxcvbn