ci: use larger resource_class

.circleci/config.yml

@@ -5,7 +5,7 @@ jobs:
     docker:
       - image: circleci/golang:1.12.1-stretch
     working_directory: ~/go/src/github.com/filecoin-project/go-sectorbuilder
-    resource_class: xlarge
+    resource_class: 2xlarge
     steps:
       - configure_environment_variables
       - run:
@@ -31,7 +31,7 @@ jobs:
     macos:
       xcode: "10.0.0"
     working_directory: ~/go/src/github.com/filecoin-project/go-sectorbuilder
-    resource_class: medium
+    resource_class: large
     steps:
       - configure_environment_variables
       - run:
@@ -123,4 +123,3 @@ commands:
           key: v15-proof-params-{{ arch }}
           paths:
             - "~/filecoin-proof-parameters/"
-