Fix for issue #780

Ceedling could not handle test filenames that included dashes, specifically when those filenames became key names in the `:defines:` section of the project file. All other aspects of a dashed filename for source or test C files appears to work without issue.

The issue was in the automated creation of the internal configurator object’s accessor methods. In the case of `:defines:` entries, key names became Ruby method names. Dashes are illegal in Ruby method names. The fix was simply to replace any dashes with underscores in generated Ruby method names inserted into configurator.

Given the limits on allowed C filename characters, Ruby method names, and practical conventions, dashes _should_ be the only complicating character in filenames.

lib/ceedling/configurator_builder.rb

@@ -27,9 +27,12 @@ def build_global_constants(config)
 
 
   def build_accessor_methods(config, context)
+    # Fill configurator object with accessor methods
     config.each_pair do |key, value|
-      # fill configurator object with accessor methods
-      eval("def #{key.to_s.downcase}() return @project_config_hash[:#{key}] end", context)
+      # Convert key names to Ruby method names
+      # Some key names can be C file names that can include dashes; dashes are not allowed in Ruby method names
+      # Downcase the key names for consistency and replace any illegal dashes with legal underscores
+      eval("def #{key.to_s.gsub('-','_').downcase}() return @project_config_hash[:#{key}] end", context)
     end
   end