Remove unnecessary dependency on lyber-core

Gemfile

@@ -35,7 +35,6 @@ gem 'uuidtools', '~> 2.1.4'
 
 # DLSS/domain-specific dependencies
 gem 'dor-services', '~> 7.0'
-gem 'lyber-core', '>= 2.0.2'
 
 group :test, :development do
   gem 'coveralls', '~> 0.8', require: false

Gemfile.lock

@@ -150,14 +150,6 @@ GEM
       faraday_middleware
       net-http-persistent (>= 2.9.4, < 4.a)
       nokogiri (~> 1.6)
-    dor-workflow-service (2.12.0)
-      activesupport (>= 3.2.1, < 6)
-      confstruct (>= 0.2.7, < 2)
-      deprecation
-      faraday (~> 0.9, >= 0.9.2)
-      net-http-persistent (>= 2.9.4, < 4.a)
-      nokogiri (~> 1.6)
-      retries
     druid-tools (1.0.0)
     dry-configurable (0.8.2)
       concurrent-ruby (~> 1.0)
@@ -222,9 +214,6 @@ GEM
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
-    lyber-core (4.1.5)
-      activesupport
-      dor-workflow-service (>= 1.7, < 3)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     marc (1.0.3)
@@ -462,7 +451,6 @@ DEPENDENCIES
   honeybadger
   jwt
   listen (~> 3.0.5)
-  lyber-core (>= 2.0.2)
   marc
   net-http-persistent (~> 2.9)
   okcomputer