add new parameter class

src/main/java/gov/usgs/earthquake/nshmp/www/meta/Parameter.java

+package gov.usgs.earthquake.nshmp.www.meta;
+
+@SuppressWarnings("unused")
+public class Parameter {
+
+  private final String display;
+  private final String value;
+
+  public Parameter(String display, String value) {
+    this.display = display;
+    this.value = value;
+  }
+}