Add coveralls

.coveralls.yml

@@ -0,0 +1 @@
+service_name: travis-pro

.travis.yml

@@ -1,10 +1,42 @@
 language: rust
+
+# See travis-ci/travis-ci#9061
+sudo: required
+
+# Cache cargo symbols for faster build
 cache: cargo
+
+# Dependencies of kcov, used by coverage
+addons:
+  apt:
+    packages:
+      - libcurl4-openssl-dev
+      - libelf-dev
+      - libdw-dev
+      - binutils-dev
+      - cmake # also required for cargo-update
+    sources:
+      - kalakris-cmake
+
+# run builds for all the trains (and more)
 rust:
   - stable
   - beta
   - nightly
+
 matrix:
   allow_failures:
     - rust: nightly
-  fast_finish: true
+  fast_finish: true
+
+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+  - cargo install-update -a # update outdated cached binaries
+  - pip install --user python-coveralls
+
+after_success:
+# measure code coverage and upload to coveralls.io
+  - cargo coveralls --exclude-pattern /libargon2-sys,/tests,/beserial -p nimiq
+  - coveralls --merge=target/kcov/merged-kcov-output/coveralls.out