Check that bin/cordova works on Travis CI (#343) (#344)

Ensure that bin script actually runs on current Node.js version
to detect and avoid bugs such as apache/cordova-cli#339

Co-authored-by: Christopher J. Brody <chris.brody@gmail.com>
Co-authored-by: Jan Piotrowski <piotrowski+github@gmail.com>
diff --git a/.travis.yml b/.travis.yml
index e13dac7..4105e07 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,3 +11,9 @@
   - "6"
   - "8"
   - "10"
+
+before_script:
+  # Ensure that bin script actually runs on used Node.js version
+  # to detect and avoid bugs such as apache/cordova-cli#339
+  # (<https://github.com/apache/cordova-cli/issues/339>)
+  - ./bin/cordova --version