Openpgp security update (V2) (#31)

* Change keyring unlock functionalities

* Add keyring#Lock, keyring#CheckIntegrity, tests

* Update helpers, fix bugs

* Update go.mod with ProtonMail/crypto commit

* Change key management system

* Clear keys from memory + tests

* Create SessionKey with direct encryption for datapackets. Move symmetrickey to password.

* Fix upstream dependencies

* Update module to V2, documentation

* Add linter

* Add v2 folder to .gitignore

* Minor changes to KeyID getters

* Remove old changelog

* Improve docs, remove compilation script

internal/armor.go

@@ -1,8 +1,9 @@
 package internal
 
 import (
-	"golang.org/x/crypto/openpgp/armor"
 	"strings"
+
+	"golang.org/x/crypto/openpgp/armor"
 )
 
 // Unarmor unarmors an armored string.

internal/common.go

@@ -4,7 +4,7 @@ package internal
 import (
 	"regexp"
 
-	"github.com/ProtonMail/gopenpgp/constants"
+	"github.com/ProtonMail/gopenpgp/v2/constants"
 )
 
 // TrimNewlines removes whitespace from the end of each line of the input