Updating commits-since badge to omnia-v0.2

Signed-off-by: Lucas A. Wilson <luke.wilson@dell.com>

README.md

@@ -1,6 +1,6 @@
 <img src="docs/images/omnia-logo.png" width="500px">
 
-![GitHub](https://img.shields.io/github/license/dellhpc/omnia) ![GitHub issues](https://img.shields.io/github/issues-raw/dellhpc/omnia) ![GitHub release (latest by date including pre-releases)](https://img.shields.io/github/v/release/dellhpc/omnia?include_prereleases) ![GitHub last commit (branch)](https://img.shields.io/github/last-commit/dellhpc/omnia/devel) ![GitHub commits since tagged version](https://img.shields.io/github/commits-since/dellhpc/omnia/omnia-v0.1/devel) 
+![GitHub](https://img.shields.io/github/license/dellhpc/omnia) ![GitHub issues](https://img.shields.io/github/issues-raw/dellhpc/omnia) ![GitHub release (latest by date including pre-releases)](https://img.shields.io/github/v/release/dellhpc/omnia?include_prereleases) ![GitHub last commit (branch)](https://img.shields.io/github/last-commit/dellhpc/omnia/devel) ![GitHub commits since tagged version](https://img.shields.io/github/commits-since/dellhpc/omnia/omnia-v0.2/devel) 
 
 #### Ansible playbook-based deployment of Slurm and Kubernetes on Dell EMC PowerEdge servers running an RPM-based Linux OS