chore: add unstable vue version to peer deps (#91)

This should allow using the beta versions of Vue without issuing a warning

Author: posva

package.json

@@ -37,7 +37,7 @@
   },
   "peerDependencies": {
     "@vue/composition-api": "^1.0.0-rc.1",
-    "vue": "^3.0.0 || ^2.6.0"
+    "vue": "^3.0.0-0 || ^2.6.0"
   },
   "peerDependenciesMeta": {
     "@vue/composition-api": {