--passwordenv doesn't work for for unlock (#347)

* - Add passwordenv parameter to unlock command
- Add passwordfile parameter to unlock command
- Adapt help message

* Remove newline

* Add warning if passwordenv var not found

* Appease the linter

* Refactor

* Undo last commit

src/program.ts

@@ -202,6 +202,8 @@ export class Program extends BaseProgram {
                 }
                 this.processResponse(Response.error('Vault is locked.'), true);
             })
+            .option('--passwordenv <passwordenv>', 'Environment variable storing your password')
+            .option('--passwordfile <passwordfile>', 'Path to a file containing your password as its first line')
             .action(async (password, cmd) => {
                 if (!cmd.check) {
                     await this.exitIfNotAuthed();