Add Basic Auth to the gateway

Add and enable basic auth to the gateway. This allows users to
put their gateway on the internet and expose it to public networks
without anyone being able to control their deployments.

Added information to the README that allows users to get their
gatewau basic auth password and username

Signed-off-by: Alistair Hey <alistair@heyal.co.uk>

vendor/github.com/sethvargo/go-password/password/mock.go

@@ -0,0 +1,39 @@
+package password
+
+// Built-time checks that the generators implement the interface.
+var _ PasswordGenerator = (*mockGenerator)(nil)
+
+type mockGenerator struct {
+	result string
+	err    error
+}
+
+// NewMockGenerator creates a new generator that satisfies the PasswordGenerator
+// interface. If an error is provided, the error is returned. If a result if
+// provided, the result is always returned, regardless of what parameters are
+// passed into the Generate or MustGenerate methods.
+//
+// This function is most useful for tests where you want to have predicable
+// results for a transitive resource that depends on go-password.
+func NewMockGenerator(result string, err error) *mockGenerator {
+	return &mockGenerator{
+		result: result,
+		err:    err,
+	}
+}
+
+// Generate returns the mocked result or error.
+func (g *mockGenerator) Generate(int, int, int, bool, bool) (string, error) {
+	if g.err != nil {
+		return "", g.err
+	}
+	return g.result, nil
+}
+
+// MustGenerate returns the mocked result or panics if an error was given.
+func (g *mockGenerator) MustGenerate(int, int, int, bool, bool) string {
+	if g.err != nil {
+		panic(g.err)
+	}
+	return g.result
+}