first pass at upgrading dependencies

- use tilde ranges for dependencies
- use fixed version for dependencies that should not automatically upgrade
- regenerate lock file

package.json

@@ -11,49 +11,49 @@
     "node": ">= 8.0.0"
   },
   "devDependencies": {
-    "@octokit/rest": "^15.11.1",
-    "asciidoctor.js": "1.5.6",
-    "autoprefixer": "^9.1.5",
-    "browserify": "^16.2.2",
-    "chokidar": "^2.0.4",
-    "cssnano": "^4.1.0",
-    "docsearch.js": "2.5.2",
-    "eslint": "^5.5.0",
-    "eslint-config-standard": "^12.0.0",
-    "eslint-plugin-import": "^2.14.0",
-    "eslint-plugin-node": "^7.0.1",
-    "eslint-plugin-promise": "^4.0.0",
-    "eslint-plugin-standard": "^4.0.0",
-    "gulp": "^3.9.1",
-    "gulp-concat": "^2.6.1",
-    "gulp-connect": "^5.6.1",
-    "gulp-eslint": "^5.0.0",
-    "gulp-imagemin": "^4.1.0",
-    "gulp-postcss": "^8.0.0",
-    "gulp-stylelint": "^7.0.0",
-    "gulp-uglify": "^3.0.1",
-    "gulp-vinyl-zip": "^2.1.0",
-    "handlebars": "^4.0.11",
-    "highlight.js": "9.12.0",
-    "jquery": "^3.3.1",
-    "js-yaml": "^3.12.0",
-    "map-stream": "^0.0.7",
-    "mark.js": "^8.11.1",
-    "merge-stream": "^1.0.1",
-    "npm-which": "^3.0.1",
-    "postcss": "^7.0.2",
-    "postcss-calc": "^6.0.1",
-    "postcss-custom-properties": "^7.0.0",
-    "postcss-import": "^12.0.0",
-    "postcss-syntax": "^0.33.0",
-    "postcss-url": "^8.0.0",
-    "prettier-eslint-cli": "^4.7.1",
-    "require-from-string": "^2.0.2",
-    "stylelint": "^9.5.0",
-    "stylelint-config-standard": "^18.2.0",
-    "typeface-roboto-condensed": "^0.0.54",
-    "typeface-roboto-mono": "^0.0.54",
-    "vinyl-buffer": "^1.0.1",
-    "vinyl-fs": "^3.0.3"
+    "@octokit/rest": "~15.18",
+    "asciidoctor.js": "1.5.9",
+    "autoprefixer": "~9.4",
+    "browserify": "~16.2",
+    "chokidar": "~3.0",
+    "cssnano": "~4.1",
+    "docsearch.js": "~2.6",
+    "eslint": "~5.11",
+    "eslint-config-standard": "~12.0",
+    "eslint-plugin-import": "~2.14",
+    "eslint-plugin-node": "~8.0",
+    "eslint-plugin-promise": "~4.0",
+    "eslint-plugin-standard": "~4.0",
+    "gulp": "~3.9",
+    "gulp-concat": "~2.6",
+    "gulp-connect": "~5.7",
+    "gulp-eslint": "~5.0",
+    "gulp-imagemin": "~4.1",
+    "gulp-postcss": "~8.0",
+    "gulp-stylelint": "~8.0",
+    "gulp-uglify": "~3.0",
+    "gulp-vinyl-zip": "~2.1 >=2.1.2",
+    "handlebars": "~4.0",
+    "highlight.js": "9.13.1",
+    "jquery": "~3.4",
+    "js-yaml": "~3.12",
+    "map-stream": "0.0.7",
+    "mark.js": "~8.11",
+    "merge-stream": "~1.0",
+    "npm-which": "~3.0",
+    "postcss": "~7.0",
+    "postcss-calc": "~7.0",
+    "postcss-custom-properties": "~8.0",
+    "postcss-import": "~12.0",
+    "postcss-syntax": "~0.36",
+    "postcss-url": "~8.0",
+    "prettier-eslint-cli": "~4.7",
+    "require-from-string": "~2.0",
+    "stylelint": "~9.9",
+    "stylelint-config-standard": "~18.2",
+    "typeface-roboto-condensed": "0.0.54",
+    "typeface-roboto-mono": "0.0.54",
+    "vinyl-buffer": "~1.0",
+    "vinyl-fs": "~3.0"
   }
 }