bootstrap is no longer a runtime dependency, it is built into the dist files

bower.json

@@ -19,7 +19,7 @@
   "moduleType": "globals",
   "main": [
     "scss/bootstrap-material-design.scss",
-    "dist/js/bootstrap-material-design.js"
+    "dist/bootstrap-material-design.js"
   ],
   "ignore": [
     "/.*",
@@ -31,12 +31,7 @@
     "js/tests",
     "test-infra"
   ],
-  "x-private-dependencies": {
-    "bootstrap": "git@github.com:rosskevin/bootstrap.git#v4-tmp-flex-master",
-    "tether": "^1.1"
-  },
   "dependencies": {
-    "bootstrap": "v4-dev",
-    "tether": "^1.1"
+    "tether": "^1.2"
   }
 }

package.json

@@ -33,12 +33,12 @@
   },
   "license": "MIT",
   "dependencies": {
-    "bootstrap": "twbs/bootstrap#v4-dev",
     "babel-polyfill": "^6.6",
     "jquery": "^2.2",
     "tether": "^1.2.0"
   },
   "devDependencies": {
+    "bootstrap": "twbs/bootstrap#v4-dev",
     "babel-core": "^6.7.2",
     "babel-eslint": ">=6.0.0-beta.6",
     "babel-preset-es2015": "^6.6.0",