Added --all to c8 command

refs https://github.com/TryGhost/Toolbox/issues/203

- without `--all`, c8 ignores files that should be included in the
  coverage score but aren't used in tests
- this means we have artificially high scores in places where this
  isn't used
- this commit adds `--all` where previously missing
- where this fails `--check-coverage`, that has been removed for
  now

ghost/custom-theme-settings-service/package.json

@@ -7,7 +7,7 @@
   "main": "index.js",
   "scripts": {
     "dev": "echo \"Implement me!\"",
-    "test": "NODE_ENV=testing c8 --reporter text --reporter cobertura --check-coverage mocha './test/**/*.test.js'",
+    "test": "NODE_ENV=testing c8 --all --reporter text --reporter cobertura --check-coverage mocha './test/**/*.test.js'",
     "lint": "eslint . --ext .js --cache",
     "posttest": "yarn lint"
   },

ghost/email-analytics-provider-mailgun/package.json

@@ -7,7 +7,7 @@
   "main": "index.js",
   "scripts": {
     "dev": "echo \"Implement me!\"",
-    "test": "NODE_ENV=testing c8 --reporter text --reporter cobertura --check-coverage mocha './test/**/*.test.js'",
+    "test": "NODE_ENV=testing c8 --all --reporter text --reporter cobertura --check-coverage mocha './test/**/*.test.js'",
     "lint": "eslint . --ext .js --cache",
     "posttest": "yarn lint"
   },

ghost/email-analytics-service/package.json

@@ -7,7 +7,7 @@
   "main": "index.js",
   "scripts": {
     "dev": "echo \"Implement me!\"",
-    "test": "NODE_ENV=testing c8 --reporter text --reporter cobertura mocha './test/**/*.test.js'",
+    "test": "NODE_ENV=testing c8 --all --reporter text --reporter cobertura mocha './test/**/*.test.js'",
     "lint": "eslint . --ext .js --cache",
     "posttest": "yarn lint"
   },