Revert "Added code coverage with cargo-travis."

It seems to hit an internal compiler error, so, that's not a great plan.

This reverts commit 5612c50f5a.

.travis.yml

@@ -1,28 +1,6 @@
 language: rust
 rust: stable
-sudo: true
-
-cache:
-  - apt
-  - cargo
-
-addons:
-  apt:
-    packages:
-      - libcurl4-openssl-dev
-      - libelf-dev
-      - libdw-dev
-      - binutils-dev
-      - cmake
-    sources:
-      - kalakris-cmake
-
-before_script:
-  - export PATH=$HOME/.cargo/bin:$PATH
-  - cargo install cargo-update || echo "cargo-update already installed"
-  - cargo install cargo-travis || echo "cargo-travis already installed"
-  - cargo install-update -a # update outdated cached binaries
-
+sudo: false
 script:
   - chmod +x mktestconfig.sh
   - ./mktestconfig.sh
@@ -31,10 +9,6 @@ script:
   - cargo test --verbose --features "toml yaml"
   - cargo test --doc
   - cargo test --verbose --no-default-features
-
-after_success:
-  - cargo coveralls
-
 notifications:
   email: false
   irc: