Grand test fixup (#138)

* start fixing up tests

* fix up tests + automate with drone

* fiddle with linting

* messing about with drone.yml

* some more fiddling

* hmmm

* add cache

* add vendor directory

* verbose

* ci updates

* update some little things

* update sig

vendor/github.com/golang/geo/s2/regionunion.go

@@ -0,0 +1,66 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package s2
+
+// A RegionUnion represents a union of possibly overlapping regions.
+// It is convenient for computing a covering of a set of regions.
+type RegionUnion []Region
+
+// CapBound returns a bounding cap for this RegionUnion.
+func (ru RegionUnion) CapBound() Cap { return ru.RectBound().CapBound() }
+
+// RectBound returns a bounding latitude-longitude rectangle for this RegionUnion.
+func (ru RegionUnion) RectBound() Rect {
+	ret := EmptyRect()
+	for _, reg := range ru {
+		ret = ret.Union(reg.RectBound())
+	}
+	return ret
+}
+
+// ContainsCell reports whether the given Cell is contained by this RegionUnion.
+func (ru RegionUnion) ContainsCell(c Cell) bool {
+	for _, reg := range ru {
+		if reg.ContainsCell(c) {
+			return true
+		}
+	}
+	return false
+}
+
+// IntersectsCell reports whether this RegionUnion intersects the given cell.
+func (ru RegionUnion) IntersectsCell(c Cell) bool {
+	for _, reg := range ru {
+		if reg.IntersectsCell(c) {
+			return true
+		}
+	}
+	return false
+}
+
+// ContainsPoint reports whether this RegionUnion contains the Point.
+func (ru RegionUnion) ContainsPoint(p Point) bool {
+	for _, reg := range ru {
+		if reg.ContainsPoint(p) {
+			return true
+		}
+	}
+	return false
+}
+
+// CellUnionBound computes a covering of the RegionUnion.
+func (ru RegionUnion) CellUnionBound() []CellID {
+	return ru.CapBound().CellUnionBound()
+}