Added Opa.gitignore
Added Opa.gitignore

A .gitignore template for the Opa language <http://opalang.org>

bruennijs/ise.cppworkshop,szymanskirafal/gitignore,bruennijs/ise.cppworkshop,chhsieh/gitTest_1,szymanskirafal/gitignore,hirochachacha/gitignore-generator,bruennijs/ise.cppworkshop,chhsieh/helloworld,szymanskirafal/gitignore