Spell check strings and comments

Signed-off-by: Jhon Honce <jhonce@redhat.com>

Closes: #831
Approved by: rhatdan

test/e2e/libpod_suite_test.go

@@ -254,7 +254,7 @@ func (s *PodmanSession) OutputToStringArray() []string {
 	return strings.Split(output, "\n")
 }
 
-// IsJSONOutputValid attempts to unmarshall the session buffer
+// IsJSONOutputValid attempts to unmarshal the session buffer
 // and if successful, returns true, else false
 func (s *PodmanSession) IsJSONOutputValid() bool {
 	var i interface{}