Commit Gemfile.lock for reproducible tests

Addressed a syntax error in the thrift.gemspec, and committed
Gemfile.lock files for both the gem and tests. Gems source switched
to https://rubygems.org.

This is a strongly recommended approach according to the Bundler team:

> As a result, you SHOULD check your Gemfile.lock into version control,
> in both applications and gems. If you do not, every machine that
> checks out your repository (including your production server) will
> resolve all dependencies again, which will result in different
> versions of third-party code being used if any of the gems in the
> Gemfile(5) or any of their dependencies have been updated.
https://bundler.io/man/bundle-install.1.html#THE-GEMFILE-LOCK

Also helps with Dependabot, which will be able to bump the lock file,
while we can relax version requirements in the gemspec.
diff --git a/test/rb/Gemfile b/test/rb/Gemfile
index 4ff0539..c75f7a0 100644
--- a/test/rb/Gemfile
+++ b/test/rb/Gemfile
@@ -1,6 +1,4 @@
-source "http://rubygems.org"
-
-require "rubygems"
+source "https://rubygems.org"
 
 gem 'rack', '~> 2.0', '>= 2.0.4'
 gem 'thin', '~> 1.7', '>= 1.7.2'
diff --git a/test/rb/Gemfile.lock b/test/rb/Gemfile.lock
new file mode 100644
index 0000000..8e64418
--- /dev/null
+++ b/test/rb/Gemfile.lock
@@ -0,0 +1,28 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    daemons (1.4.1)
+    eventmachine (1.2.7)
+    power_assert (3.0.1)
+    rack (2.2.21)
+    test-unit (3.7.3)
+      power_assert
+    thin (1.8.2)
+      daemons (~> 1.0, >= 1.0.9)
+      eventmachine (~> 1.0, >= 1.0.4)
+      rack (>= 1, < 3)
+
+PLATFORMS
+  arm64-darwin
+  arm64-linux
+  ruby
+  x86_64-darwin
+  x86_64-linux
+
+DEPENDENCIES
+  rack (~> 2.0, >= 2.0.4)
+  test-unit (~> 3.2, >= 3.2.7)
+  thin (~> 1.7, >= 1.7.2)
+
+BUNDLED WITH
+   2.2.34