fix: ignore missing config keys when getting the current mob

if we don't have the git-mob.co-author key then there is no mob

resolves #67 #68

features/git-mob/bugs/67-getallglobal-errors-when-soloing.feature

@@ -1,6 +1,5 @@
-@wip
-@announce-gitmob-log
-@announce-stdout @announce-stderr
+#@announce-gitmob-log
+#@announce-stdout @announce-stderr
 Feature: 🐛 GetAllGlobal(git-mob.co-author): nonzero exit code: 1: (when soloing)
 
   Background:

internal/gitConfig/atoms.go

@@ -38,7 +38,9 @@ func GetGlobal(key string) string {
 // GetAll gets all values for a multi-valued option key.
 func GetAll(key string) ([]string, error) {
 	o, exitCode, err := shell.SilentRun("git", "config", "--get-all", key)
-	if err != nil {
+	if ExitCode(exitCode) == SectionOrKeyIsInvalid {
+		return make([]string, 0), nil
+	} else if err != nil {
 		return make([]string, 0), ExitCode(exitCode).Errorf(err)
 	}
 	return strings.Split(o, "\n"), nil
@@ -47,7 +49,9 @@ func GetAll(key string) ([]string, error) {
 // GetAllGlobal gets all values for a multi-valued option key.
 func GetAllGlobal(key string) ([]string, error) {
 	o, exitCode, err := shell.SilentRun("git", "config", "--global", "--get-all", key)
-	if err != nil {
+	if ExitCode(exitCode) == SectionOrKeyIsInvalid {
+		return make([]string, 0), nil
+	} else if err != nil {
 		return make([]string, 0), ExitCode(exitCode).Errorf(err)
 	}
 	return strings.Split(o, "\n"), nil