remove generated.rs file from git (#750)

.gitignore

@@ -1,6 +1,8 @@
 # Generated by Cargo
 # will have compiled files and executables
 /target/
+# generated file by build.rs for mapping nmap-payloads to rust
+src/generated.rs
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html