Fix return value types in jsdoc

src/decodeCert.js

@@ -2,10 +2,11 @@ import base64url from 'base64url'
 import decodeUriComponent from 'decode-uri-component'
 import untildify from 'untildify'
 import { isAbsolute } from './utils'
+
 /**
  * decode a tls certificate from a base64 encoded url string.
  * @param  {String} certString base64url encoded string to decode
- * @return {Promise} decoded certificate
+ * @return {String} decoded certificate
  */
 const decodeCert = certString => {
   if (!certString) {

src/decodeMacaroon.js

@@ -6,7 +6,7 @@ import { isAbsolute } from './utils'
 /**
  * decode a binary macaroon as a base64 decoded url string.
  * @param  {String} macaroonPath Path to macaroon file.
- * @return {Promise} decoded macaroon
+ * @return {String} decoded macaroon
  */
 const decodeMacaroon = macaroonString => {
   if (!macaroonString) {

src/encodeCert.js

@@ -4,7 +4,7 @@ import strictUriEncode from 'strict-uri-encode'
 /**
  * Encode a tls certificate as a base64 encoded url string.
  * @param  {String} certPath Path to vertificate file.
- * @return {Promise} Encoded certificate
+ * @return {String} Encoded certificate
  */
 const encodeCert = (input, format = 'utf8') => {
   if (!input) {

src/encodeMacaroon.js

@@ -4,7 +4,7 @@ import strictUriEncode from 'strict-uri-encode'
 /**
  * Encode a binary macaroon as a base64 encoded url string.
  * @param  {String} macaroonPath Path to macaroon file.
- * @return {Promise} Encoded macaroon
+ * @return {String} Encoded macaroon
  */
 const encodeMacaroon = (input, format = 'hex') => {
   if (!input) {