Don't commit Gemfile.lock

Current best practice is to commit this
https://bundler.io/man/bundle-install.1.html#THE-GEMFILE-LOCK
but we have zero deps, so it doesn't make sense

.gitignore

@@ -12,3 +12,7 @@
 __pycache__/
 /composer.lock
 /package-lock.json
+# Current best practice is to commit this
+# https://bundler.io/man/bundle-install.1.html#THE-GEMFILE-LOCK
+# but we have zero deps, so it doesn't make sense
+Gemfile.lock

Gemfile

@@ -2,5 +2,3 @@ source "https://rubygems.org"
 
 # Specify your gem's dependencies in pincode-validator.gemspec
 gemspec
-
-gem "rake", "~> 12.0"

Gemfile.lock

@@ -1,34 +0,0 @@
-PATH
-  remote: .
-  specs:
-    pincode_validator (1.0.3)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    diff-lcs (1.3)
-    rake (12.3.3)
-    rspec (3.9.0)
-      rspec-core (~> 3.9.0)
-      rspec-expectations (~> 3.9.0)
-      rspec-mocks (~> 3.9.0)
-    rspec-core (3.9.1)
-      rspec-support (~> 3.9.1)
-    rspec-expectations (3.9.1)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.9.0)
-    rspec-mocks (3.9.1)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.9.0)
-    rspec-support (3.9.2)
-
-PLATFORMS
-  ruby
-
-DEPENDENCIES
-  pincode_validator!
-  rake (~> 12.0)
-  rspec (~> 3.8)
-
-BUNDLED WITH
-   2.1.4