Rustpkg test runs tests of an external dependency if it's already been downloaded

[sfackler]

https://github.com/sfackler/rust-postgres depends on https://github.com/sfackler/rust-ssl. When I run tests via rustpkg, the following very weird thing happens:

> git clone ssh://git@github.com/sfackler/rust-postgres.git
...
> cd rust-postgres
> env TMPDIR=$HOME/tmp rustpkg test
WARNING: The Rust package manager is experimental and may be unstable
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust

running 73 tests
...
<rust-postgres tests omitted>
> touch test.rs
> env TMPDIR=$HOME/tmp rustpkg test
WARNING: The Rust package manager is experimental and may be unstable
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust

running 10 tests
...
<rust-ssl tests omitted>
> rm -rf .rust
> env TMPDIR=$HOME/tmp rustpkg test
WARNING: The Rust package manager is experimental and may be unstable
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust
note: Installed package github.com/sfackler/rust-ssl-0.1 to /home/sfackler/test/src/rust-postgres/.rust

running 73 tests
...
<rust-postgres tests omitted>

cc @catamorphism

[catamorphism]

Looks valid. Offhand it wouldn't surprise me if rustpkg isn't caching the results of tests the way it caches build, and is re-running tests even if dependencies haven't changed.

[catamorphism]

@sfackler also pointed out that it runs different tests the first time and the second time -- running the postgres tests the first time, and the ssl tests the second time. It doesn't seem like rustpkg test should test the dependencies all, actually, just the one crate that was provided as an (explicit or implicit) argument on the command line.

[alexcrichton]

rustpkg has been removed