added feature synthetichealth#1326, middle name in patients.csv

src/main/java/org/mitre/synthea/export/CSVExporter.java

@@ -297,7 +297,7 @@ private static List<String> propStringToList(String fileListString) {
    */
   private void writeCSVHeaders() throws IOException {
     patients.write("Id,BIRTHDATE,DEATHDATE,SSN,DRIVERS,PASSPORT,"
-        + "PREFIX,FIRST,LAST,SUFFIX,MAIDEN,MARITAL,RACE,ETHNICITY,GENDER,BIRTHPLACE,"
+        + "PREFIX,FIRST,MIDDLE,LAST,SUFFIX,MAIDEN,MARITAL,RACE,ETHNICITY,GENDER,BIRTHPLACE,"
         + "ADDRESS,CITY,STATE,COUNTY,FIPS,ZIP,LAT,LON,"
         + "HEALTHCARE_EXPENSES,HEALTHCARE_COVERAGE,INCOME");
     patients.write(NEWLINE);
@@ -625,6 +625,7 @@ private String patient(Person person, long time) throws IOException {
         Person.IDENTIFIER_PASSPORT,
         Person.NAME_PREFIX,
         Person.FIRST_NAME,
+        Person.MIDDLE_NAME,
         Person.LAST_NAME,
         Person.NAME_SUFFIX,
         Person.MAIDEN_NAME,
@@ -2021,4 +2022,4 @@ private OutputStreamWriter getWriter(Path outputDirectory, String filename, bool
     append = append && file.exists();
     return new OutputStreamWriter(new FileOutputStream(file, append), charset);
   }
-}
+}