updated .travis.yml. it seems that docs token has been changed so far?
renamed `Encoder`/`Decoder` to `RawEncoder`/`RawDecoder`.

the old type names remain as deprecated since the custom trap used
them and it was a reasonably public interface (even show-cased in
the README). they will be removed before 1.0. the methods making
them are not-so-public and have been immediately renamed.
fixed remaining occurrences of old names and wrong substitutions.
Fix for latest rustc
Make index_tests.rs its own crate, used by the other index-* crates.

Avoid using

    #[path = "../index_tests.rs"]
    mod tests;

… which doesn’t work nicely with crates.io.
Merge pull request #58 from canndrew/master

Fix for latest rustc
Merge pull request #59 from SimonSapin/publish

Make index_tests.rs its own crate, used by the other index-* crates.
`cargo publish` needs the version for `encoding_index_tests`.
added metadata to every Cargo.toml.