Port osbuild/images v0.33.0 with dot-notation to composer

Update the osbuild/images to the version which introduces "dot notation"
for distro release versions.

 - Replace all uses of distroregistry by distrofactory.
 - Delete local version of reporegistry and use the one from the
   osbuild/images.
 - Weldr: unify `createWeldrAPI()` and `createWeldrAPI2()` into a single
   `createTestWeldrAPI()` function`.
 - store/fixture: rework fixtures to allow overriding the host distro
   name and host architecture name. A cleanup function to restore the
   host distro and arch names is always part of the fixture struct.
 - Delete `distro_mock` package, since it is no longer used.
 - Bump the required version of osbuild to 98, because the OSCAP
   customization is using the 'compress_results' stage option, which is
   not available in older versions of osbuild.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

vendor/github.com/docker/go-connections/sockets/proxy.go

@@ -0,0 +1,51 @@
+package sockets
+
+import (
+	"net"
+	"net/url"
+	"os"
+	"strings"
+
+	"golang.org/x/net/proxy"
+)
+
+// GetProxyEnv allows access to the uppercase and the lowercase forms of
+// proxy-related variables.  See the Go specification for details on these
+// variables. https://golang.org/pkg/net/http/
+func GetProxyEnv(key string) string {
+	proxyValue := os.Getenv(strings.ToUpper(key))
+	if proxyValue == "" {
+		return os.Getenv(strings.ToLower(key))
+	}
+	return proxyValue
+}
+
+// DialerFromEnvironment takes in a "direct" *net.Dialer and returns a
+// proxy.Dialer which will route the connections through the proxy using the
+// given dialer.
+func DialerFromEnvironment(direct *net.Dialer) (proxy.Dialer, error) {
+	allProxy := GetProxyEnv("all_proxy")
+	if len(allProxy) == 0 {
+		return direct, nil
+	}
+
+	proxyURL, err := url.Parse(allProxy)
+	if err != nil {
+		return direct, err
+	}
+
+	proxyFromURL, err := proxy.FromURL(proxyURL, direct)
+	if err != nil {
+		return direct, err
+	}
+
+	noProxy := GetProxyEnv("no_proxy")
+	if len(noProxy) == 0 {
+		return proxyFromURL, nil
+	}
+
+	perHost := proxy.NewPerHost(proxyFromURL, direct)
+	perHost.AddFromString(noProxy)
+
+	return perHost, nil
+}