message: fix ordering of paragraph properties
  strXmlParaSpc needs to be after strXmlLnSpc in order for them both
  to take effect.
  observed previous behavior: applying paraSpaceBefore and lineSpacing
  together would result in only paraSpaceBefore being visible in PPT.
diff: @@ -4229,8 +4229,9 @@ var PptxGenJS = function(){
  }
  // Close Paragraph-Properties --------------------
  - // IMPORTANT: strXmlLnSpc must precede strXmlBullet for bullet lineSpacing to work (PPT-Online)
  - paragraphPropXml += '>'+ strXmlParaSpc + strXmlLnSpc + strXmlBullet;
  + // IMPORTANT: strXmlLnSpc, strXmlParaSpc, and strXmlBullet require strict ordering.
  + // anything out of order is ignored. (PPT-Online, PPT for Mac)
  + paragraphPropXml += '>' + strXmlLnSpc + strXmlParaSpc + strXmlBullet;
  if (isDefault) {
  paragraphPropXml += genXmlTextRunProperties(textObj.options, true);
  }
  