+ Adding /neighbor/remove route api code and db-lib code

This patch has not yet been tested but will be in the coming patches

Sumamary: we're just doing a regular delete on the neighbor's table based off
the url field

json-api/db/src/neighbors.rs

@@ -73,3 +73,10 @@ pub async fn update(p: &Pool, url: &str, new: Neighbor) -> SqlResult<()> {
     conn.exec_drop(q, sqlparams).await?;
     Ok(())
 }
+
+pub async fn remove(p: &Pool, url: &str) -> SqlResult<()> {
+    let mut conn = p.get_conn().await?;
+    let q = "DELETE FROM neighbors WHERE url = :url";
+    conn.exec_drop(q, params!{"url" => url}).await?;
+    Ok(())
+}