Change the console message when there are no tests to run

[srinivasreddy]

when you don't have any tests to run,

$ cargo test
   Compiling rand v0.1.0 (https://github.com/rust-lang-nursery/rand.git#9f35b8e)
   Compiling hello_world v0.1.0 (file:///path/to/project/hello_world)
     Running target/test/hello_world-9c2b65bbb79eabce

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

How about showing,

cargo test
There are no tests to run 
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

cargo test --  hello
There are no tests to run  in 'hello'
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

[alexcrichton]

Unfortunately this is somewhat up to the underlying test harnesses as Cargo doesn't understand a lot about what each underlying binary is doing

[kornelski]

Related/dupe #2832

[alexcrichton]

Ah yes, indeed!