Fix test and i386 CI (#171)

* Fix tests

* Replace apt-fast with apt-get

.github/workflows/ci.yml

@@ -66,8 +66,8 @@ jobs:
         if: runner.os == 'Linux' && matrix.target.cpu == 'i386'
         run: |
           sudo dpkg --add-architecture i386
-          sudo apt-fast update -qq
-          sudo DEBIAN_FRONTEND='noninteractive' apt-fast install \
+          sudo apt-get update -qq
+          sudo DEBIAN_FRONTEND='noninteractive' apt-get install \
             --no-install-recommends -yq gcc-multilib g++-multilib \
             libssl-dev:i386
           mkdir -p external/bin

tests/test_json_marshalling.nim

@@ -79,6 +79,13 @@ proc rand[T](_: type seq[T]): seq[T] =
   for i in 0..<3:
     result[i] = rand(T)
 
+proc rand(_: type array[3, seq[byte]]): array[3, seq[byte]] =
+  var z = newSeq[byte](10)
+  discard randomBytes(z)
+  result[0] = z
+  result[1] = z
+  result[2] = z
+
 proc rand[T](_: type SingleOrList[T]): SingleOrList[T] =
   SingleOrList[T](kind: slkSingle, single: rand(T))