Vue packages version mismatch:

- vue@2.6.12
- vue-template-compiler@2.5.17

This may cause things to work incorrectly. Make sure to use the same version for both.
If you are using vue-loader@>=10.0, simply update vue-template-compiler.
If you are using vue-loader@<10.0 or vueify, re-installing vue-loader/vueify should bump vue-template-compiler to the latest.

    at Object.<anonymous> (/Users/ham/Desktop/Projects/ProofU/frontend/node_modules/vue-template-compiler/index.js:8:9)
    at Module._compile (internal/modules/cjs/loader.js:1128:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1167:10)
    at Module.load (internal/modules/cjs/loader.js:983:32)
    at Function.Module._load (internal/modules/cjs/loader.js:891:14)
    at Module.require (internal/modules/cjs/loader.js:1023:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/Users/ham/Desktop/Projects/ProofU/frontend/node_modules/vue-loader/lib/parser.js:1:18)
    at Module._compile (internal/modules/cjs/loader.js:1128:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1167:10)
 @ ./src/router/index.js 13:0-50
 @ ./src/main.js
 @ multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./src/main.js