fix(fvt): disable keepalive on toxiproxy client

We don't want to keep the tcp conn alive as we only make very few
requests and it'll show up as a leaked goroutine in-between tests.

Signed-off-by: Dominic Evans <dominic.evans@uk.ibm.com>

internal/toxiproxy/client.go

@@ -24,7 +24,8 @@ func NewClient(endpoint string) *Client {
 					KeepAlive: 30 * time.Second,
 				}).DialContext,
 				ForceAttemptHTTP2:     true,
-				MaxIdleConns:          100,
+				MaxIdleConns:          -1,
+				DisableKeepAlives:     true,
 				IdleConnTimeout:       90 * time.Second,
 				TLSHandshakeTimeout:   10 * time.Second,
 				ExpectContinueTimeout: 1 * time.Second,