Added user login and account creation

backend/src/main/java/achievements/data/User.java

@@ -0,0 +1,43 @@
+package achievements.data;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class User {
+
+	@JsonProperty("email")
+	public String email;
+	@JsonProperty("username")
+	public String username;
+	@JsonProperty("password")
+	public String password;
+
+	public User(String email, String username, String password) {
+		this.email = email;
+		this.username = username;
+		this.password = password;
+	}
+
+	public String getEmail() {
+		return email;
+	}
+
+	public void setEmail(String email) {
+		this.email = email;
+	}
+
+	public String getUsername() {
+		return username;
+	}
+
+	public void setUsername(String username) {
+		this.username = username;
+	}
+
+	public String getPassword() {
+		return password;
+	}
+
+	public void setPassword(String password) {
+		this.password = password;
+	}
+}