Support uint in InDelta and InEpsilon

InDelta and InEpsilon assertions on uint values would fail with
the error "Parameters must be numerical".

Author: dpw

assert/assertions.go

@@ -1110,6 +1110,8 @@ func toFloat(x interface{}) (float64, bool) {
 	xok := true
 
 	switch xn := x.(type) {
+	case uint:
+		xf = float64(xn)
 	case uint8:
 		xf = float64(xn)
 	case uint16:

assert/assertions_test.go

@@ -1306,6 +1306,7 @@ func TestInDelta(t *testing.T) {
 		a, b  interface{}
 		delta float64
 	}{
+		{uint(2), uint(1), 1},
 		{uint8(2), uint8(1), 1},
 		{uint16(2), uint16(1), 1},
 		{uint32(2), uint32(1), 1},