Many small improvements in automatic testing and deployment

.travis.yml

@@ -4,6 +4,8 @@ node_js:
     - "8"
     - "7"
     - "6"
+    - "5"
+    - "4"
 
 os:
     - linux
@@ -18,7 +20,7 @@ before_install:
     - npm install --global codacy-coverage
 
 install:
-    - npm install --only=development
+    - npm install
 
 script:
     - npm run check
@@ -35,6 +37,8 @@ jobs:
           node_js: "8"
           os: "linux"
           before_deploy:
+            - git stash --all
+            - npm install
             - npm run build
           deploy:
             provider: npm