Update test scripts to accept full URL instead of LB_IP

- test-metrics.sh and test-metrics.py now take a full URL with port
- Supports both HTTP and HTTPS endpoints
- Updated README with new usage examples

README.md

@@ -75,7 +75,9 @@ kubectl -n m3db get svc m3coordinator-lb
 
 **Quick connectivity test:**
 ```bash
-./test-metrics.sh <LB_IP>
+./test-metrics.sh <BASE_URL>
+# Example:
+./test-metrics.sh https://m3db.vultrlabs.dev:7201
 ```
 
 This script verifies:
@@ -87,7 +89,9 @@ This script verifies:
 **Full read/write test (Python):**
 ```bash
 pip install requests python-snappy
-python3 test-metrics.py <LB_IP>
+python3 test-metrics.py <BASE_URL>
+# Example:
+python3 test-metrics.py https://m3db.vultrlabs.dev:7201
 ```
 
 Writes a test metric via Prometheus remote_write and reads it back.