fix build

Author: Georgi Peltekov

.travis.yml

@@ -14,10 +14,9 @@ branches:
 # We're also doing the install step here too, as we need
 # the results of previous builds to install future builds
 script:
-  - rm -f package-lock.json && yarn install
-    && yarn global add tsickle
-    && yarn global add ngx-file-drop
-    && yarn run packagr
+  - rm -f package-lock.json && npm install
+    && npm install -g ngx-file-drop
+    && npm run packagr
 # Notifications
 notifications:
   email:

package-lock.json

@@ -48,6 +48,7 @@
     "@angular/cli": "^7.0.0",
     "@angular/compiler-cli": "^7.0.0",
     "@types/node": "^8.0.53",
+    "tsickle": "^0.33.0",
     "ng-packagr": "^4.4.0",
     "ts-node": "~7.0.1",
     "tslint": "5.11.0",