Adds missing #to_s calls

lib/wpscan/db/fingerprints.rb

@@ -33,7 +33,7 @@ module WPScan
 
       # @return [ String ]
       def self.wp_fingerprints_path
-        @wp_fingerprints_path ||= DB_DIR.join('wp_fingerprints.json')
+        @wp_fingerprints_path ||= DB_DIR.join('wp_fingerprints.json').to_s
       end
 
       # @return [ Hash ]

lib/wpscan/db/plugin.rb

@@ -4,7 +4,7 @@ module WPScan
     class Plugin < WpItem
       # @return [ String ]
       def self.db_file
-        @db_file ||= DB_DIR.join('plugins.json')
+        @db_file ||= DB_DIR.join('plugins.json').to_s
       end
     end
   end

lib/wpscan/db/theme.rb

@@ -4,7 +4,7 @@ module WPScan
     class Theme < WpItem
       # @return [ String ]
       def self.db_file
-        @db_file ||= DB_DIR.join('themes.json')
+        @db_file ||= DB_DIR.join('themes.json').to_s
       end
     end
   end

lib/wpscan/db/wp_version.rb

@@ -4,7 +4,7 @@ module WPScan
     class Version < WpItem
       # @return [ String ]
       def self.db_file
-        @db_file ||= DB_DIR.join('wordpresses.json')
+        @db_file ||= DB_DIR.join('wordpresses.json').to_s
       end
     end
   end