add generic Certificate model

internal/certificates/models.go

@@ -0,0 +1,18 @@
+package certificates
+
+// GenericCertificate is a generic container to enable us to
+// handle both certificates and keys with one function
+type GenericCertificate struct {
+	Name     string
+	FilePath string
+	Secret   string
+
+	// True if key, false if certificate
+	IsKey bool
+
+	// Bytes fetched from the server
+	serverBytes []byte
+
+	// Bytes fetched from disk
+	diskBytes []byte
+}