Fix travis build error

.travis.yml

@@ -22,7 +22,7 @@ before_install:
 
 # Build
 script:
-- rm -f package-lock.json && npm install
+- npm install
 - npm run packagr
 - ng test --watch=false
 - ng e2e

package.json

@@ -31,14 +31,14 @@
   },
   "devDependencies": {
     "@angular-devkit/build-angular": "~0.11.0",
-    "@angular/cli": "^7.1.4",
-    "@angular/common": "^7.1.4",
-    "@angular/compiler": "^7.1.4",
-    "@angular/compiler-cli": "^7.1.4",
-    "@angular/core": "^7.1.4",
-    "@angular/forms": "^7.1.4",
-    "@angular/platform-browser": "^7.1.4",
-    "@angular/platform-browser-dynamic": "^7.1.4",
+    "@angular/cli": "^7.0.0",
+    "@angular/common": "^7.0.0",
+    "@angular/compiler": "^7.0.0",
+    "@angular/compiler-cli": "^7.0.0",
+    "@angular/core": "^7.0.0",
+    "@angular/forms": "^7.0.0",
+    "@angular/platform-browser": "^7.0.0",
+    "@angular/platform-browser-dynamic": "^7.0.0",
     "@types/jasmine": "~2.8.8",
     "@types/jasminewd2": "~2.0.3",
     "@types/node": "~8.9.4",
@@ -57,14 +57,14 @@
     "tsickle": "^0.34.0",
     "tslib": "^1.9.0",
     "tslint": "^5.11.0",
-    "typescript": "^3.1.6",
+    "typescript": ">=3.1.1 <3.2",
     "zone.js": "^0.8.26"
   },
   "peerDependencies": {
-    "@angular/common": "^7.1.4",
-    "@angular/core": "^7.1.4",
-    "@angular/forms": "^7.1.4",
-    "@angular/platform-browser": "^7.1.4",
+    "@angular/common": "^7.0.0",
+    "@angular/core": "^7.0.0",
+    "@angular/forms": "^7.0.0",
+    "@angular/platform-browser": "^7.0.0",
     "zone.js": "^0.8.26"
   }
 }