Feat: Created Geohash class and its skeletton Esri#213

src/main/java/com/esri/core/geometry/Geohash.java

@@ -0,0 +1,45 @@
+package com.esri.core.geometry;
+
+
+/**
+ * Helper class to work with geohash
+ */
+public class Geohash {
+
+    /**
+     * Create an evelope from a given geohash
+     * @param geoHash
+     * @return The envelope that corresponds to the geohash
+     */
+    public static Envelope2D geohashToEnvelope(String geoHash){
+        return null;
+    }
+
+    /**
+     * Computes the geohash that contains a point at a certain precision
+     * @param pt 
+     * @param characterLength - The precision of the geohash
+     * @return The geohash of containing pt as a String
+     */
+    public static String toGeohash(Point2D pt, int characterLength){
+        return "";
+    }
+
+    /**
+     * Compute the longest geohash that contains the envelope
+     * @param envelope
+     * @return the geohash as a string
+     */
+    public static String containingGeohash(Envelope2D envelope){
+        return "";
+    }
+
+    /**
+     * 
+     * @param envelope 
+     * @return up to four geohashes that completely cover given envelope
+     */
+    public static String[] coveringGeohash(Envelope2D envelope){
+        return new String[]{};
+    }
+}