create error module for services

src/service/error.rs

@@ -0,0 +1,20 @@
+use std::fmt;
+
+pub type Result<T> = std::result::Result<T, ServicesError>;
+
+#[derive(Debug, Copy, Clone)]
+pub enum ServicesError {
+   ResonseError(&'static str),
+}
+
+impl std::error::Error for ServicesError {}
+
+impl fmt::Display for ServicesError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> std::fmt::Result {
+        match *self {
+            ServicesError::ResonseError(ref err) =>  write!(f, "Response: {}", err),
+        }
+    }
+}
+
+