Support for git references

lib/github.js

@@ -7,7 +7,8 @@ import download from 'download'
 import tmp from 'tmp-promise'
 
 const downloadRepo = async repoPath => {
-  const url = `https://api.github.com/repos/${repoPath}/tarball`
+  const pathParts = gitPathParts(repoPath)
+  const url = `https://api.github.com/repos/${pathParts.main}/tarball/${pathParts.ref}`
 
   const tmpDir = await tmp.dir({
     // We'll remove it manually once deployment is done
@@ -31,6 +32,19 @@ const downloadRepo = async repoPath => {
   return tmpDir
 }
 
+export const gitPathParts = main => {
+  let ref = ''
+
+  if (main.split('/')[1].includes('#')) {
+    const parts = main.split('#')
+
+    ref = parts[1]
+    main = parts[0]
+  }
+
+  return {main, ref}
+}
+
 export const isRepoPath = path => {
   if (!path) {
     return false