Get latest purescript from github in .travis.yml

Author: klntsky

.travis.yml

@@ -13,14 +13,15 @@ env:
   matrix:
   - PATH=$HOME/purescript:$PATH
 
-install:
-- export PURS_VERSION=v0.13.3
-- wget -O $HOME/purescript.tar.gz https://github.com/purescript/purescript/releases/download/$PURS_VERSION/linux64.tar.gz
-- tar -xvf $HOME/purescript.tar.gz -C $HOME/
-- chmod a+x $HOME/purescript
-- npm install -g spago
-- npm install
-- spago install
+install: |
+  PURS_VERSION="$(curl -H "Authorization: token $GITHUB_API_TOKEN" --silent "https://api.github.com/repos/purescript/purescript/releases/latest" | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/')"
+  echo "PureScript version: $PURS_VERSION"
+  wget -O $HOME/purescript.tar.gz https://github.com/purescript/purescript/releases/download/$PURS_VERSION/linux64.tar.gz
+  tar -xvf $HOME/purescript.tar.gz -C $HOME/
+  chmod a+x $HOME/purescript
+  npm install -g spago
+  npm install
+  spago install
 
 script:
 - npm run build