Update development dependencies to solve error

Author: andyw8

Gemfile.lock

@@ -0,0 +1,38 @@
+PATH
+  remote: .
+  specs:
+    readwise (1.0.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.6.2)
+    rake (13.3.0)
+    rspec (3.13.1)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.5)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.5)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-file_fixtures (0.1.9)
+      rspec (~> 3.12)
+    rspec-mocks (3.13.5)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.4)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  bundler (~> 2.6)
+  rake (~> 13.0)
+  readwise!
+  rspec (~> 3.0)
+  rspec-file_fixtures (~> 0.1.6)
+
+BUNDLED WITH
+   2.6.9

readwise.gemspec

@@ -37,8 +37,8 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "bundler", "~> 2.2"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "bundler", "~> 2.6"
+  spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.0"
   spec.add_development_dependency "rspec-file_fixtures", "~> 0.1.6"
 end