Update Tulsi to Xcode 11.3.1.

PiperOrigin-RevId: 308281606
diff --git a/.bazelrc b/.bazelrc
index 58b310a..fe92af6 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -1,6 +1,6 @@
 build --cpu=darwin_x86_64
 build --apple_platform_type=macos
-build --xcode_version=11.2.1
+build --xcode_version=11.3.1
 
 # Disable the Swift compilation worker when running integration tests, since it
 # requires the protobuf dependency which is infeasible to get working on Bazel.
diff --git a/.travis.yml b/.travis.yml
index 8cfbc1f..62ba0fb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 os: osx
 language: swift
 # macOS images: https://docs.travis-ci.com/user/reference/osx#macos-version
-osx_image: xcode11.2
+osx_image: xcode11.3
 
 before_install:
   - brew tap bazelbuild/tap
diff --git a/src/TulsiGeneratorIntegrationTests/BazelIntegrationTestCase.swift b/src/TulsiGeneratorIntegrationTests/BazelIntegrationTestCase.swift
index bf0a0f2..6badfff 100644
--- a/src/TulsiGeneratorIntegrationTests/BazelIntegrationTestCase.swift
+++ b/src/TulsiGeneratorIntegrationTests/BazelIntegrationTestCase.swift
@@ -89,7 +89,7 @@
 
     // Explicitly set Xcode version to use. Must use the same version or the golden files
     // won't match.
-    bazelBuildOptions.append("--xcode_version=11.2.1")
+    bazelBuildOptions.append("--xcode_version=11.3.1")
 
     // Disable the Swift worker as it adds extra dependencies.
     bazelBuildOptions.append("--define=RULES_SWIFT_BUILD_DUMMY_WORKER=1")
diff --git a/src/TulsiGeneratorIntegrationTests/update_goldens.sh b/src/TulsiGeneratorIntegrationTests/update_goldens.sh
index 852c4d1..e836e9d 100755
--- a/src/TulsiGeneratorIntegrationTests/update_goldens.sh
+++ b/src/TulsiGeneratorIntegrationTests/update_goldens.sh
@@ -17,7 +17,7 @@
 
 # Update this whenever the version of Xcode needed to generate the goldens
 # changes.
-readonly XCODE_VERSION=11.2.1
+readonly XCODE_VERSION=11.3.1
 
 readonly WORKSPACE=$(bazel info workspace)
 readonly TEST_PATH="src/TulsiGeneratorIntegrationTests"