ci: use standard libp2p travis script

.travis.yml

+os:
+  - linux
+
 language: go
+
 go:
-  - 1.11.x
-  - 1.12.x
-  - 1.13.x
-  - tip
-before_install:
-  - travis_retry go get github.com/mattn/goveralls
+  - 1.14.x
+  - 1.15.x
+
+env:
+  global:
+    - GOTFLAGS="-race"
+  matrix:
+    - BUILD_DEPTYPE=gomod
+
+
+# disable travis install
+install:
+  - true
+
 script:
-  - go test -v -covermode=count -coverprofile=coverage.out ./...
-  - travis_retry $HOME/gopath/bin/goveralls -coverprofile=coverage.out -service=travis-ci
+  - 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