Add contract that `log` is an export from the client crate

Cargo.toml

@@ -10,4 +10,6 @@ proc-macro = true
 [dependencies]
 syn = {version = "1.0.16", features = ["full", "extra-traits"]}
 quote = "1.0.2"
+
+[dev-dependencies]
 log = "0.4.8"
\ No newline at end of file

src/lib.rs

@@ -34,8 +34,8 @@ pub fn timed(_attr_ts: TokenStream, fn_ts: TokenStream) -> TokenStream {
             let mut inner = || { #inner_block };
             let ret = inner();
 
-            log::trace!(
-                "Elapsed {}: {:?}",
+            crate::log::trace!(
+                "Duration of `{}`: {:?}",
                 #original_func_name,
                 timer.elapsed()
             );

tests/tests.rs

+use log;
 use micro_timer::timed;
 use std::time::Duration;