Update dependencies & fix misc formatting errors

src/util/support/path/SSHFilesystem.ts

@@ -5,6 +5,7 @@ import * as fs from 'fs'
 import {Readable, Writable} from 'stream'
 import {Collection} from '../../collection/Collection'
 import {UniversalPath} from '../path'
+import {Maybe} from '../types'
 
 /**
  * A Filesystem implementation that stores files on remote hosts via SFTP/SSH.
@@ -190,7 +191,7 @@ export class SSHFilesystem extends Filesystem {
         const sftp = await this.getSFTP()
         const metaPath = this.metadataPath(storePath)
         await new Promise<void>((res, rej) => {
-            sftp.writeFile(metaPath, JSON.stringify(meta), err => {
+            sftp.writeFile(metaPath, JSON.stringify(meta), (err: Maybe<Error>) => {
                 if ( err ) {
                     rej(err)
                 } else {