This closes #855, fix missing formula cell when getting rows value

rows.go

@@ -165,7 +165,7 @@ func rowXMLHandler(rowIterator *rowXMLIterator, xmlElement *xml.StartElement) {
 		}
 		blank := rowIterator.cellCol - len(rowIterator.columns)
 		val, _ := colCell.getValueFrom(rowIterator.rows.f, rowIterator.d)
-		if val != "" {
+		if val != "" || colCell.F != nil {
 			rowIterator.columns = append(appendSpace(blank, rowIterator.columns), val)
 		}
 	}

rows_test.go

@@ -138,12 +138,18 @@ func TestRowHeight(t *testing.T) {
 	// Test set row height with custom default row height with prepare XML.
 	assert.NoError(t, f.SetCellValue(sheet1, "A10", "A10"))
 
+	f.NewSheet("Sheet2")
+	assert.NoError(t, f.SetCellValue("Sheet2", "A2", true))
+	height, err = f.GetRowHeight("Sheet2", 1)
+	assert.NoError(t, err)
+	assert.Equal(t, 15.0, height)
+
 	err = f.SaveAs(filepath.Join("test", "TestRowHeight.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	convertColWidthToPixels(0)
+	assert.Equal(t, 0.0, convertColWidthToPixels(0))
 }
 
 func TestColumns(t *testing.T) {

stream.go

@@ -333,7 +333,7 @@ func (sw *StreamWriter) SetRow(axis string, values []interface{}) error {
 }
 
 // SetColWidth provides a function to set the width of a single column or
-// multiple columns for the the StreamWriter. Note that you must call
+// multiple columns for the StreamWriter. Note that you must call
 // the 'SetColWidth' function before the 'SetRow' function. For example set
 // the width column B:C as 20:
 //