chore(tests) add Short() -> SkipNow() to slowest tests

vanilla:
    21.57 real        45.14 user         8.51 sys

short:
    14.40 real        31.13 user         5.56 sys

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

bitswap_test.go

@@ -90,6 +90,9 @@ func TestGetBlockFromPeerAfterPeerAnnounces(t *testing.T) {
 }
 
 func TestSwarm(t *testing.T) {
+	if testing.Short() {
+		t.SkipNow()
+	}
 	net := tn.VirtualNetwork()
 	rs := mock.VirtualRoutingServer()
 	sg := NewSessionGenerator(net, rs)