tests: use stages for the travis execution (#967)

* tests: use stages for the travis execution

Fixes #694

* add comments as suggested by @nventuro

* move the unit tests first, as suggested by @frangio

* make stages clearer as suggested by @nventuro

* tests: use stages for the travis execution

Fixes #694

* add comments as suggested by @nventuro

* move the unit tests first, as suggested by @frangio

* make stages clearer as suggested by @nventuro

* update the stage names as suggested by @frangio

* Run all tests in parallel

* added names

scripts/test.sh

@@ -59,6 +59,8 @@ if [ "$SOLC_NIGHTLY" = true ]; then
   wget -q https://raw.githubusercontent.com/ethereum/solc-bin/gh-pages/bin/soljson-nightly.js -O /tmp/soljson.js && find . -name soljson.js -exec cp /tmp/soljson.js {} \;
 fi
 
+truffle version
+
 if [ "$SOLIDITY_COVERAGE" = true ]; then
   node_modules/.bin/solidity-coverage