set the testEnvironment as node by default (#231)

Author: jadbox

package.json

@@ -49,6 +49,7 @@
     "transform": {
       ".(ts|tsx)": "<rootDir>/node_modules/ts-jest/preprocessor.js"
     },
+    "testEnvironment": "node",
     "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
     "moduleFileExtensions": [
       "ts",