Added deploy script and fixed package namespace issue (#46)

* Convert to HTTP handlers inside outside of the main package

Previously, the top-level package exported functions with the
signature `func(*util.Context) util.StatusError`, and the `main`
package was responsible for wrapping these and producing normal
HTTP handlers. However, the Google Cloud Functions execution
environment expects to be able to invoke HTTP handlers which are
exported directly from the top-level package.

We move the logic of converting these inner handlers into HTTP
handlers to the `internal/util` package, allowing us to expose
HTTP handlers from the top-level package

* Added deploy script and fixed package namespace issue

- functions package renamed to upload-token.functions
- added CheckHTTPS function to detect HTTP calls from headers
- added HSTS header
- updated README.md
- updated Postman JSON file

Co-authored-by: Joshua Liebow-Feeser <[email protected]>

.gcloudignore

@@ -0,0 +1,20 @@
+# This file specifies files that are *not* uploaded to Google Cloud Platform
+# using gcloud. It follows the same syntax as .gitignore, with the addition of
+# "#!include" directives (which insert the entries of the given .gitignore-style
+# file at that point).
+#
+# For more information, run:
+#   $ gcloud topic gcloudignore
+#
+.gcloudignore
+# If you would like to upload your .git directory, .gitignore file or files
+# from your .gitignore file, remove the corresponding line
+# below:
+.git
+.gitignore
+
+#!include:.gitignore
+.firebase.json
+.firestore.indexes.json
+firestore.rules
+.github