Add kcov support (#545)

* Adding kcov code coverage to chain and core modules
* Adjust travis.yml to wget kcov from mimblewimble org
* Add codecov badge to README.md
* Fix repo name in badge to grin, from kcov

.travis.yml

@@ -12,7 +12,12 @@ addons:
     packages:
       - g++-5
       - cmake
-
+      - libcurl4-openssl-dev
+      - libelf-dev
+      - libdw-dev
+      - cmake
+      - gcc
+      - binutils-dev 
 env:
   global:
     - RUST_BACKTRACE="1"
@@ -29,4 +34,29 @@ env:
     - TEST_DIR=core
     - TEST_DIR=util
 
+after_success: |
+  pwd &&
+  echo "HERE" &&
+  wget https://github.com/mimblewimble/kcov/archive/master.tar.gz &&
+  tar xzf master.tar.gz &&
+  cd kcov-master &&
+  mkdir build &&
+  cd build &&
+  cmake .. &&
+  make &&
+  sudo make install &&
+  cd ../.. &&
+  rm -rf kcov-master &&
+  cargo test --no-run &&
+  cd ../
+  pwd &&
+  kcov --exclude-pattern=/.cargo,/usr/lib --verify target/cov target/debug/grin_core* && 
+  echo "Finished coverage for grin_core"
+  kcov --exclude-pattern=/.cargo,/usr/lib --verify target/cov target/debug/grin_chain* && 
+  echo "Finished coverage for grin_chain"
+  kcov --exclude-pattern=/.cargo,/usr/lib --verify target/cov target/debug/mine_simple_* &&
+  echo "Finished coverage for mine_simple"
+  bash <(curl -s https://codecov.io/bash) &&
+  echo "Uploaded code coverage"
+
 script: cd $TEST_DIR && cargo test --verbose

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/mimblewimble/grin.svg?branch=master)](https://travis-ci.org/mimblewimble/grin) [![Gitter chat](https://badges.gitter.im/grin_community/Lobby.png)](https://gitter.im/grin_community/Lobby)
+[![Build Status](https://travis-ci.org/mimblewimble/grin.svg?branch=master)](https://travis-ci.org/mimblewimble/grin) [![Gitter chat](https://badges.gitter.im/grin_community/Lobby.png)](https://gitter.im/grin_community/Lobby) [![Codecov coverage status](https://codecov.io/gh/mimblewimble/grin/branch/master/graph/badge.svg)](https://codecov.io/gh/mimblewimble/grin)
 
 # Grin