Removed Prime signature and tests

Gemfile

@@ -17,7 +17,6 @@ gem "goodcheck"
 gem "dbm"
 gem 'digest'
 gem 'tempfile'
-gem "prime"
 gem "rdoc", "~> 6.4.0"
 
 # Test gems

Gemfile.lock

@@ -17,7 +17,6 @@ GEM
     dbm (1.1.0)
     diff-lcs (1.5.0)
     digest (3.1.1)
-    forwardable (1.3.2)
     goodcheck (3.1.0)
       marcel (>= 1.0, < 2.0)
       psych (>= 3.1, < 5.0)
@@ -35,9 +34,6 @@ GEM
       racc
     power_assert (2.0.3)
     prettier_print (1.2.1)
-    prime (0.1.2)
-      forwardable
-      singleton
     psych (4.0.6)
       stringio
     public_suffix (5.0.1)
@@ -82,7 +78,6 @@ GEM
       sorbet-runtime
       syntax_tree (>= 6.1.1, < 7)
     ruby-progressbar (1.13.0)
-    singleton (0.1.1)
     sorbet-runtime (0.5.10827)
     stackprof (0.2.25)
     stringio (3.0.7)
@@ -105,7 +100,6 @@ DEPENDENCIES
   json
   json-schema
   minitest
-  prime
   rake
   rake-compiler
   rbs!