Update Nim to 1.6.10 (#321)

* Update Nim to 1.6.4

Hoping this version has the CVE fixed.

* Update main.yml

* Update .github/workflows/main.yml

Co-authored-by: ringabout <[email protected]>

Author: dom96

.github/workflows/main.yml

@@ -18,7 +18,7 @@ jobs:
       matrix:
         firefox: [ '73.0' ]
         include:
-          - nim-version: '1.6.0'
+          - nim-version: '1.6.10'
             cache-key: 'stable'
     steps:
       - uses: actions/checkout@v2