switch from log to tracing

I think this is a big improvement in readability.

I removed the `lnav` config, which is a little sad, but I don't think it
supports this structured logging format well. Still seems worthwhile on
balance.

server/db/upgrade/mod.rs

@@ -8,11 +8,11 @@
 
 use crate::db;
 use failure::{bail, Error};
-use log::info;
 use nix::NixPath;
 use rusqlite::params;
 use std::ffi::CStr;
 use std::io::Write;
+use tracing::info;
 use uuid::Uuid;
 
 mod v0_to_v1;

server/db/upgrade/v0_to_v1.rs

@@ -6,9 +6,9 @@
 use crate::db;
 use crate::recording;
 use failure::Error;
-use log::warn;
 use rusqlite::{named_params, params};
 use std::collections::HashMap;
+use tracing::warn;
 
 pub fn run(_args: &super::Args, tx: &rusqlite::Transaction) -> Result<(), Error> {
     // These create statements match the schema.sql when version 1 was the latest.

server/db/upgrade/v4_to_v5.rs

@@ -10,13 +10,13 @@ use crate::db::SqlUuid;
 use crate::{dir, schema};
 use cstr::cstr;
 use failure::{bail, Error, Fail};
-use log::info;
 use nix::fcntl::{FlockArg, OFlag};
 use nix::sys::stat::Mode;
 use protobuf::Message;
 use rusqlite::params;
 use std::io::{Read, Write};
 use std::os::unix::io::AsRawFd;
+use tracing::info;
 use uuid::Uuid;
 
 const FIXED_DIR_META_LEN: usize = 512;

server/db/upgrade/v6_to_v7.rs

@@ -5,9 +5,9 @@
 /// Upgrades a version 6 schema to a version 7 schema.
 use failure::{format_err, Error, ResultExt};
 use fnv::FnvHashMap;
-use log::debug;
 use rusqlite::{named_params, params};
 use std::{convert::TryFrom, path::PathBuf};
+use tracing::debug;
 use url::Url;
 use uuid::Uuid;