Improve Dockerfile to reduce image size

[tdurieux]

Hi there,

I've made a small improvement to the Dockerfile that I think could help optimize the image size.

The change I made:

• I remove the yum cache after the yum install which reduces the size of the final image.

Impact on the image size:

• Image size before repair: 1.39 GB
• Image size after repair: 832.68 MB
• Difference: 586.33 MB (41.32%)

I hope that you will find these changes useful to you. Let me know if you have any questions or concerns.

Thanks,