chore(ci): switch to circle and test with both race enabled & disabled

.circleci/config.yml

+version: 2.1
+orbs:
+  ci-go: ipfs/ci-go@0.2
+
+workflows:
+  version: 2
+  test:
+    jobs:
+      - ci-go/build
+      - ci-go/lint
+      - ci-go/test
+      - ci-go/test:
+          race: true
+          name: "ci-go/test/race"

.travis.yml

-os:
-  - linux
-
-language: go
-
-go:
-  - 1.11.x
-
-env:
-  global:
-    - GOTFLAGS="-race"
-    - BUILD_DEPTYPE=gomod
-
-# disable travis install
-install:
-  - true
-
-script:
-  - bash <(curl -s https://raw.githubusercontent.com/ipfs/ci-helpers/master/travis-ci/run-standard-tests.sh)
-
-
-cache:
-  directories:
-    - $GOPATH/pkg/mod
-    - $HOME/.cache/go-build
-
-notifications:
-  email: false