Roll Observatory packages and add a roll script

packages/petitparser/tool/travis.sh

Index: packages/petitparser/tool/travis.sh
diff --git a/packages/petitparser/tool/travis.sh b/packages/petitparser/tool/travis.sh
new file mode 100755
index 0000000000000000000000000000000000000000..ae843214cf2918512f39917bc8379c2b51c9a143
--- /dev/null
+++ b/packages/petitparser/tool/travis.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+# Fast fail the script on failures.
+set -e
+
+# Verify that the libraries are error free.
+dartanalyzer --fatal-warnings \
+  lib/*.dart \
+  test/*.dart
+
+# Verify that all the tests pass.
+pub run test
+
+# Verify the coverage of the tests.
+if [ "$COVERALLS_TOKEN" ] && [ "$TRAVIS_DART_VERSION" = "stable" ]; then
+  pub global activate dart_coveralls
+  pub global run dart_coveralls report \
+    --token $COVERALLS_TOKEN \
+    --retry 2 \
+    --exclude-test-files \
+    test/all_tests.dart
+fi