Cleanup: add unit test for parsing backslashes in variable values

Backslashes can be included in two ways, as-is (which works fine) and
between double quotes (in which case they need escaping). This test checks
for both.

internal/manager/config/config_test.go

@@ -0,0 +1,20 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestVariablesWithBackslashes(t *testing.T) {
+	c, err := loadConf("test_files/config_with_backslashes.yaml")
+	require.NoError(t, err)
+
+	vars := c.VariablesLookup[VariableAudienceUsers]
+	expectSingle := `C:\Downloads\blender-1.0\blender.exe`
+	expectDouble := `C:\\Downloads\\blender-1.0\\blender.exe`
+	assert.Equal(t, expectSingle, vars["single-backslash"]["blender"])
+	assert.Equal(t, expectDouble, vars["double-backslash"]["blender"])
+	assert.Equal(t, expectSingle, vars["quoted-double-backslash"]["blender"])
+}

internal/manager/config/test_files/config_with_backslashes.yaml

@@ -0,0 +1,24 @@
+# File for use in unit tests
+#
+# This file has variable definitions with various ways to include backslashes in
+# values.
+
+_meta:
+  version: 3
+manager_name: Backslash Tester
+database: flamenco-manager-backslash-tester.sqlite
+listen: :8123
+autodiscoverable: false
+local_manager_storage_path: ./flamenco-manager-storage
+shared_storage_path: ./tmp/flamenco-shared-storage
+shaman:
+  enabled: false
+variables:
+  blender:
+    values:
+      - platform: single-backslash
+        value: C:\Downloads\blender-1.0\blender.exe
+      - platform: double-backslash
+        value: C:\\Downloads\\blender-1.0\\blender.exe
+      - platform: quoted-double-backslash
+        value: "C:\\Downloads\\blender-1.0\\blender.exe"