edge_distances: fix test (golang#106)

The fixture for TestEdgeDistancesUpdateMinInteriorDistanceRejectionTestIsConservative
is confusing; it seems to 'want' `false` but actually it is being ignored and the test is expecting `true`.

Use `want` and change the value to `true`.

This agrees with C++:
https://github.com/google/s2geometry/blob/58de4ea1e2f8a294e0c072c602c22232fd1433ad/src/s2/s2edge_distances_test.cc#L204

Author: missinglink

s2/edge_distances_test.go

@@ -202,26 +202,26 @@ func TestEdgeDistancesUpdateMinInteriorDistanceRejectionTestIsConservative(t *te
 			a:       Point{r3.Vector{X: 1, Y: -8.9031850507928352e-11, Z: 0}},
 			b:       Point{r3.Vector{X: -0.99999999999996347, Y: 2.7030110029169596e-07, Z: 1.555092348806121e-99}},
 			minDist: minDist,
-			want:    false,
+			want:    true,
 		},
 		{
 			x:       Point{r3.Vector{X: 1, Y: -4.7617930898495072e-13, Z: 0}},
 			a:       Point{r3.Vector{X: -1, Y: -1.6065916409055676e-10, Z: 0}},
 			b:       Point{r3.Vector{X: 1, Y: 0, Z: 9.9964883247706732e-35}},
 			minDist: minDist,
-			want:    false,
+			want:    true,
 		},
 		{
 			x:       Point{r3.Vector{X: 1, Y: 0, Z: 0}},
 			a:       Point{r3.Vector{X: 1, Y: -8.4965026896454536e-11, Z: 0}},
 			b:       Point{r3.Vector{X: -0.99999999999966138, Y: 8.2297529603339328e-07, Z: 9.6070344113320997e-21}},
 			minDist: minDist,
-			want:    false,
+			want:    true,
 		},
 	}
 
 	for _, test := range tests {
-		if _, ok := UpdateMinDistance(test.x, test.a, test.b, test.minDist); !ok {
+		if _, ok := UpdateMinDistance(test.x, test.a, test.b, test.minDist); ok != test.want {
 			t.Errorf("UpdateMinDistance(%v, %v, %v, %v) = %v, want %v", test.x, test.a, test.b, test.minDist, ok, test.want)
 		}
 	}