add unit tests to test action and separate unit_tests.sh from test_all.sh

unit_tests.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+errors=()
+
+echo '=== Testing anglais ==='
+
+# read files
+for file in $(find tests -type f); do
+  echo "-v- Test-running file $file -v-"
+
+  if ! ./cli/cli run "$file"; then
+    echo "-x- Error -x-"
+    errors+=("$file")
+  else
+    echo "-+- Success -+-"
+  fi
+done
+
+
+if [ 0 -ne "$(wc -w <<< "${errors[@]}")" ]; then
+  echo "=x= Errors occured while executing =x="
+  echo "erroring files: $(printf '%s ' "${errors[@]}")"
+  exit 1
+else
+  echo '=+= Successfully ran all tests =+='
+fi