Fixed install script

.travis.yml

@@ -6,10 +6,13 @@ cache:
   npm: true
   directories:
     - node_modules
-before_install:
+addons:
-  - chmod +x src/postinstall.js
+  apt:
+    packages:
+      - graphviz
 install:
   - npm install
+  - npm install node-plantuml
 before_script:
   - npm install -g jshint
 script:

package.json

@@ -18,7 +18,7 @@
   },
   "scripts": {
     "test": "jest",
-    "install": "src/postinstall.js"
+    "install": "node src/postinstall.js"
   },
   "repository": {
     "type": "git",

src/postinstall.js

@@ -14,5 +14,5 @@ ncp('./sample_data/',dir, function(err){
     if(err)
         console.error(err);
     else
-        console.log('done');
+        console.log(`sample data copied to ${dir}`);
 });