##### Description Error thrown when attempting to generate Client SDK's for Swift3 and Swift4 when using an OAS3 spec. ##### Swagger-codegen version 3.0.1 Previously working in 3.0.0 ##### Steps to reproduce Attempt to generate client sdk ##### Suggest a fix/enhancement Issue appears to be due to a missing template dir. The following line returns null for config.templateDir(). https://github.com/swagger-api/swagger-codegen/blob/2807c714e0f7933696101821bb649a431ab43628/modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/AbstractGenerator.java#L96