Created the server validation

validations/server.js

@@ -0,0 +1,32 @@
+const Joi = require('joi');
+
+// The validation used when linking a new server
+module.exports.valLinkServer = Joi.object({
+    name: Joi.string()
+        .min(3).max(10)
+        .required()
+});
+
+// The validation used when installing a plugin
+module.exports.installAddon = Joi.object({
+    author: Joi.string()
+        .required(),
+    addon: Joi.string()
+        .required()
+});
+
+// The validation used when uninstalling a plugin
+module.exports.uninstallAddon = Joi.object({
+    author: Joi.string()
+        .required(),
+    addon: Joi.string()
+        .required(),
+    keepFiles: Joi.bool()
+        .required()
+});
+
+// The validation used when the server replies with the current installation status
+module.exports.statusResponse = Joi.object({
+    status: Joi.bool()
+        .required()
+});