Fixes global auto installation

[emileber]

Fixes #290

[codecov-io]

Codecov Report

Merging #291 into dev will decrease coverage by 0.15%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##              dev     #291      +/-   ##
==========================================
- Coverage   96.11%   95.95%   -0.16%     
==========================================
  Files           9        9              
  Lines         617      618       +1     
==========================================
  Hits          593      593              
- Misses         24       25       +1

Impacted Files	Coverage Δ
src/index.js	99.12% <50%> (-0.44%)	⬇️

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[emileber]

There was no test to check if the global installation worked, and even Vuex doesn't test this. So I didn't added one.

[kazupon]

Thanks!