fix: Add binary path to script.

.travis/check-format.sh

@@ -1,14 +1,14 @@
 #!/bin/bash
 cd /build/
-gcf_path="$(which git-clang-format-6.0)"
+gcf_cmd="$(which git-clang-format-6.0) --binary $(which clang-format-6.0)"
 if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then
     base_commit="HEAD^"
     echo "Running clang-format against parent commit $(git rev-parse $base_commit)"
 else
     base_commit="$TRAVIS_BRANCH"
     echo "Running clang-format against branch $base_commit, with hash $(git rev-parse $base_commit)"
 fi
-output="$($gcf_path --commit $base_commit --diff --extensions 'cpp,h')"
+output="$($gcf_cmd --commit $base_commit --diff --extensions 'cpp,h')"
 if [ "$output" == "no modified files to format" ] || [ "$output" == "clang-format did not modify any files" ]; then
     echo "clang-format passed."
     exit 0