fix(install): fail gracefully on occasional npm@2.15 hickups (#109)

* fix(install): fail gracefully on occasional npm@2.15 hickups

* docs(install): use `npm explore` to rerun install script

... as well as mention the original issue on GitHub.

bin/module-install

@@ -0,0 +1,16 @@
+#!/usr/bin/env node
+try {
+  const opt = require('opt-cli')
+  if (!opt.testOptOut('ghooks-install')) {
+    require('./install')
+  }
+} catch (e) {
+  console.warn( // eslint-disable-line no-console
+    '\nghooks postinstall could not be completed.\n' +
+    '==========================================\n\n' +
+    'Usually this is due to using npm@2.15.x. Please consider updating npm\n' +
+    'to its latest version or run the following command manually afterwards:\n\n' +
+    '\tnpm explore ghooks -- npm run install\n\n' +
+    'See https://github.com/gtramontina/ghooks/issues/71 for more information.\n'
+  )
+}

package.json

@@ -29,7 +29,7 @@
     "report-coverage": "cat ./coverage/lcov.info | node_modules/.bin/codecov",
     "validate": "npm t && npm run check-coverage",
     "commit": "git-cz",
-    "install": "opt --out ghooks-install --exec \"node ./bin/install\"",
+    "install": "node ./bin/module-install",
     "semantic-release": "semantic-release pre && npm publish && semantic-release post"
   },
   "dependencies": {