travis: chekcing if not pull request

Author: staiyeba

.travis.yml

@@ -12,7 +12,7 @@ script:
   - conan create . includeos/latest -pr apple-clang-10-macos-toolchain
   - VERSION=$(conan inspect -a version . | cut -d " " -f 2)
   - |
-    if [ "$TRAVIS_BRANCH" == "master" ]; then
+    if [[ "$TRAVIS_BRANCH" == "master" && "$TRAVIS_PULL_REQUEST" == "false" ]]; then
       conan upload --all diskbuilder/$VERSION@includeos/latest -r includeos
     fi
     if [ -n "$TRAVIS_TAG" ]; then