Add missing dots at the end of exception messages

Author: fabpot

Parser.php

@@ -207,7 +207,7 @@ private function doParse($value, $flags)
             $isRef = $mergeNode = false;
             if (self::preg_match('#^\-((?P<leadspaces>\s+)(?P<value>.+))?$#u', rtrim($this->currentLine), $values)) {
                 if ($context && 'mapping' == $context) {
-                    throw new ParseException('You cannot define a sequence item when in a mapping', $this->getRealCurrentLineNb() + 1, $this->currentLine, $this->filename);
+                    throw new ParseException('You cannot define a sequence item when in a mapping.', $this->getRealCurrentLineNb() + 1, $this->currentLine, $this->filename);
                 }
                 $context = 'sequence';
 
@@ -253,7 +253,7 @@ private function doParse($value, $flags)
                 && (false === strpos($values['key'], ' #') || \in_array($values['key'][0], ['"', "'"]))
             ) {
                 if ($context && 'sequence' == $context) {
-                    throw new ParseException('You cannot define a mapping item when in a sequence', $this->currentLineNb + 1, $this->currentLine, $this->filename);
+                    throw new ParseException('You cannot define a mapping item when in a sequence.', $this->currentLineNb + 1, $this->currentLine, $this->filename);
                 }
                 $context = 'mapping';