Change to `appraisal install`

executing to `rake appraisal:install` log

```
`rake appraisal:install` task is deprecated and will be removed soon. Please use `appraisal install`.
```
Revert "Make id partitioning for string similar to integer"

This reverts commit 068022541786e8c06caa15f864cdd0ab0569b2f7.
Merge pull request #1724 from soramugi/appraisal_install

Change to `appraisal install`