修复星座错误；新增数九、三伏。

src/main/java/com/nlf/calendar/ShuJiu.java

@@ -0,0 +1,51 @@
+package com.nlf.calendar;
+
+/**
+ * 数九
+ * @author 6tail
+ */
+public class ShuJiu {
+
+  /**
+   * 名称，如一九、二九
+   */
+  private String name;
+
+  /**
+   * 当前数九第几天，1-9
+   */
+  private int index;
+
+  public ShuJiu() {
+  }
+
+  public ShuJiu(String name, int index) {
+    this.name = name;
+    this.index = index;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public int getIndex() {
+    return index;
+  }
+
+  public void setIndex(int index) {
+    this.index = index;
+  }
+
+  @Override
+  public String toString() {
+    return name;
+  }
+
+  public String toFullString() {
+    return name + "第" + index + "天";
+  }
+}