chore(maker): upgrade electron-installer-flatpak to 0.8.0 & re-enable its tests

ci/script.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 if [[ "$TRAVIS_OS_NAME" = "linux" ]]; then
-    sudo docker run --interactive --tty --volume $(pwd):/code malept/electron-forge-container:latest /code/ci/docker.sh $NODE_INSTALLER
+    sudo docker run --privileged --interactive --tty --volume $(pwd):/code malept/electron-forge-container:latest /code/ci/docker.sh $NODE_INSTALLER
 else
     npm run test-coverage -- --installer=$NODE_INSTALLER
 fi

package.json

@@ -154,7 +154,7 @@
   "optionalDependencies": {
     "electron-installer-debian": "^0.7.1",
     "electron-installer-dmg": "^0.2.0",
-    "electron-installer-flatpak": "^0.6.0",
+    "electron-installer-flatpak": "^0.8.0",
     "electron-installer-redhat": "^0.5.0",
     "electron-windows-store": "^0.12.0",
     "electron-winstaller": "^2.5.0"

test/slow/api_spec_slow.js

@@ -311,7 +311,7 @@ describe(`electron-forge API (with installer=${nodeInstaller})`, () => {
       });
 
       function getMakers(platform) {
-        return fs.readdirSync(path.resolve(__dirname, `../../src/makers/${platform}`)).map(file => path.parse(file).name).filter(name => name !== 'flatpak');
+        return fs.readdirSync(path.resolve(__dirname, `../../src/makers/${platform}`)).map(file => path.parse(file).name);
       }
 
       const goodMakers = [...getMakers(process.platform), ...getMakers('generic')];