build: fix travis caching, run snyk only before publish command

.snyk

@@ -1,8 +1,11 @@
 # Snyk (https://snyk.io) policy file, patches or ignores known vulnerabilities.
-version: v1.13.5
+version: v1.14.1
 ignore: {}
 # patches apply the minimum changes required to fix a vulnerability
 patch:
   SNYK-JS-LODASH-450202:
     - lodash:
         patched: '2019-07-03T23:00:54.035Z'
+  SNYK-JS-LODASH-567746:
+    - lodash:
+        patched: '2020-04-30T22:28:49.705Z'

package.json

@@ -84,7 +84,7 @@
     "rollup-plugin-postcss": "^2.0.3",
     "rollup-plugin-terser": "^5.3.0",
     "semantic-release": "^17.0.0",
-    "snyk": "^1.305.0",
+    "snyk": "^1.316.1",
     "vue": "^2.6.11",
     "vue-template-compiler": "^2.6.11",
     "lodash": "^4.17.15",