Update a few dependencies

github.com/go-openapi/*
github.com/asaskevich/govalidator

vendor/github.com/go-openapi/swag/pre_go19.go

@@ -0,0 +1,55 @@
+// +build !go1.9
+
+package swag
+
+import (
+	"sort"
+	"sync"
+)
+
+// indexOfInitialisms is a thread-safe implementation of the sorted index of initialisms.
+// Before go1.9, this may be implemented with a mutex on the map.
+type indexOfInitialisms struct {
+	getMutex *sync.Mutex
+	index    map[string]bool
+}
+
+func newIndexOfInitialisms() *indexOfInitialisms {
+	return &indexOfInitialisms{
+		getMutex: new(sync.Mutex),
+		index:    make(map[string]bool, 50),
+	}
+}
+
+func (m *indexOfInitialisms) load(initial map[string]bool) *indexOfInitialisms {
+	m.getMutex.Lock()
+	defer m.getMutex.Unlock()
+	for k, v := range initial {
+		m.index[k] = v
+	}
+	return m
+}
+
+func (m *indexOfInitialisms) isInitialism(key string) bool {
+	m.getMutex.Lock()
+	defer m.getMutex.Unlock()
+	_, ok := m.index[key]
+	return ok
+}
+
+func (m *indexOfInitialisms) add(key string) *indexOfInitialisms {
+	m.getMutex.Lock()
+	defer m.getMutex.Unlock()
+	m.index[key] = true
+	return m
+}
+
+func (m *indexOfInitialisms) sorted() (result []string) {
+	m.getMutex.Lock()
+	defer m.getMutex.Unlock()
+	for k := range m.index {
+		result = append(result, k)
+	}
+	sort.Sort(sort.Reverse(byLength(result)))
+	return
+}