Remove plain JavaScript from babel-register
By default, babel-register does not compile anything in the node modules
directory. Everything in the project is now TypeScript. Therefore, only
TypeScript files need to be compiled.
diff --git a/babel-register.js b/babel-register.js
index 9aaa03e..ec45b5b 100644
--- a/babel-register.js
+++ b/babel-register.js
@@ -18,4 +18,4 @@
* under the License.
*/
-require('@babel/register')({ extensions: ['.js', '.ts'] });
+require('@babel/register')({ extensions: ['.ts'] });
