Revert "Copy GitHub SSH key in Heroku to access private repositories"

This reverts commit 2e2ecbc0a9.

Conflicts:
	package.json

heroku-copy-ssh-key-from-env.sh

@@ -1,27 +0,0 @@
-#!/usr/bin/env bash
-
-# Since we have a dependency to a private GitHub
-# `sharetribe/sharetribe-sdk-js` repository, we must give Heroku SSH
-# access to there. This script copies the GITHUB_SSH_KEY to the
-# current user to enable SSH access to the repository.
-
-# NOTE: This script should be removed when the dependency is not a
-# private repository anymore.
-
-set -e
-
-if [ -z "$GITHUB_SSH_KEY" ]
-then
-    echo "No GitHub SSH key to copy"
-    exit 0
-fi
-
-echo "Copying GitHub SSH key"
-mkdir -p ~/.ssh
-chmod 700 ~/.ssh
-echo "$GITHUB_SSH_KEY" > ~/.ssh/id_rsa
-chmod 600 ~/.ssh/id_rsa
-
-echo "Adding GitHub SSH Host key to known hosts"
-ssh-keyscan -H github.com >> ~/.ssh/known_hosts
-chmod 600 ~/.ssh/known_hosts

package.json

@@ -74,7 +74,6 @@
     "eject": "sharetribe-scripts eject",
     "start": "node server/index.js",
     "dev-server": "export NODE_ENV=development PORT=4000 REACT_APP_CANONICAL_ROOT_URL=http://localhost:4000&&yarn run build&&nodemon --watch server server/index.js",
-    "heroku-prebuild": "./heroku-copy-ssh-key-from-env.sh",
     "heroku-postbuild": "yarn run build",
     "audit": "nsp check --preprocessor yarn"
   },