VDB-327 Constantinople prep (#135)

* Bump geth to 1.8.20 for Constantinople

* Fix conflicting import/toml source for logrus

vendor/github.com/allegro/bigcache/fnv_test.go

@@ -0,0 +1,35 @@
+package bigcache
+
+import (
+	"hash/fnv"
+	"testing"
+)
+
+type testCase struct {
+	text         string
+	expectedHash uint64
+}
+
+var testCases = []testCase{
+	{"", stdLibFnvSum64("")},
+	{"a", stdLibFnvSum64("a")},
+	{"ab", stdLibFnvSum64("ab")},
+	{"abc", stdLibFnvSum64("abc")},
+	{"some longer and more complicated text", stdLibFnvSum64("some longer and more complicated text")},
+}
+
+func TestFnvHashSum64(t *testing.T) {
+	h := newDefaultHasher()
+	for _, testCase := range testCases {
+		hashed := h.Sum64(testCase.text)
+		if hashed != testCase.expectedHash {
+			t.Errorf("hash(%q) = %d want %d", testCase.text, hashed, testCase.expectedHash)
+		}
+	}
+}
+
+func stdLibFnvSum64(key string) uint64 {
+	h := fnv.New64a()
+	h.Write([]byte(key))
+	return h.Sum64()
+}