Fix rspec on ruby 2.7

Author: hammerhead

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
 
       matrix:
         os: [ "ubuntu-latest" ]
-        ruby-version: [ "2.4", "2.5", "2.6" ]
+        ruby-version: [ "2.7" ]
 
     services:
       cratedb:
@@ -54,7 +54,8 @@ jobs:
 
       - name: Bundle install
         run: |
-          gem install bundler
+          # Remove version constraint once upgrading ruby itself
+          gem install bundler -v 2.4.22
           bundle config path vendor/bundle
           bundle install
 

.ruby-version

@@ -0,0 +1 @@
+2.7.8

activerecord-crate-adapter.gemspec

@@ -46,9 +46,11 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
-  spec.add_development_dependency "rspec", "~> 2.14"
+  spec.add_development_dependency "rspec", "~> 3.13"
 
   spec.add_dependency('activerecord', '~> 4.1.0')
   spec.add_dependency('arel', '>= 5.0.0')
   spec.add_dependency('crate_ruby', '~> 0.2.0')
+  # https://github.com/ruby/bigdecimal#which-version-should-you-select
+  spec.add_dependency('bigdecimal', '~> 1.4')
 end