install swagger from source

First of all this removes the need for a network connection, second
renovate can update the version as it is tracked in go.mod.

However the real important part is that the binary downloads are
broken[1]. For some reason the swagger created with them does not
include all the type information for the examples. However when building
from source the same thing works fine.

[1] https://github.com/go-swagger/go-swagger/issues/2842

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

test/tools/vendor/github.com/go-openapi/swag/name_lexem.go

@@ -0,0 +1,87 @@
+// Copyright 2015 go-swagger maintainers
+//
+// 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 swag
+
+import "unicode"
+
+type (
+	nameLexem interface {
+		GetUnsafeGoName() string
+		GetOriginal() string
+		IsInitialism() bool
+	}
+
+	initialismNameLexem struct {
+		original          string
+		matchedInitialism string
+	}
+
+	casualNameLexem struct {
+		original string
+	}
+)
+
+func newInitialismNameLexem(original, matchedInitialism string) *initialismNameLexem {
+	return &initialismNameLexem{
+		original:          original,
+		matchedInitialism: matchedInitialism,
+	}
+}
+
+func newCasualNameLexem(original string) *casualNameLexem {
+	return &casualNameLexem{
+		original: original,
+	}
+}
+
+func (l *initialismNameLexem) GetUnsafeGoName() string {
+	return l.matchedInitialism
+}
+
+func (l *casualNameLexem) GetUnsafeGoName() string {
+	var first rune
+	var rest string
+	for i, orig := range l.original {
+		if i == 0 {
+			first = orig
+			continue
+		}
+		if i > 0 {
+			rest = l.original[i:]
+			break
+		}
+	}
+	if len(l.original) > 1 {
+		return string(unicode.ToUpper(first)) + lower(rest)
+	}
+
+	return l.original
+}
+
+func (l *initialismNameLexem) GetOriginal() string {
+	return l.original
+}
+
+func (l *casualNameLexem) GetOriginal() string {
+	return l.original
+}
+
+func (l *initialismNameLexem) IsInitialism() bool {
+	return true
+}
+
+func (l *casualNameLexem) IsInitialism() bool {
+	return false
+}