Remove ppc64le support from .travis.yml (#6180)

Travis CI for ppc64le stays in queued state.
Removing the support for now.

.travis.yml

@@ -22,21 +22,9 @@ matrix:
         - make coverage
         - node --version
         - cd browser && yarn && yarn test && cd ..
-    - os: linux-ppc64le
-      env:
-        - ARCH=ppc64le
-      go: 1.10.1
-      script:
-        - make
-        - diff -au <(gofmt -s -d cmd) <(printf "")
-        - diff -au <(gofmt -s -d pkg) <(printf "")
-        - make test GOFLAGS="-timeout 15m -v"
-        - make coverage
-        - node --version
-        - cd browser && yarn && yarn test && cd ..
 
 before_install:
 - nvm install stable
 
 after_success:
-- bash <(curl -s https://codecov.io/bash)
+- bash <(curl -s https://codecov.io/bash)