feat: first class and JUNIT test

src/src/main/java/com/theophilecosse/client/FTPClient.java

+package com.theophilecosse.client;
+
+/**
+ * FTPClient
+ */
+public class FTPClient {
+
+    private String ip;
+
+    public  FTPClient(String ip){
+        this.ip = ip;
+    }
+    
+}
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