Add "base" library. Add checked mode tester.
Made checked mode check an assert.
Renamed base library to testing.
Moved async and time test code under testing.
Throw StateError explicitly instead of using assert. Document thrown exception.
Moved lib/src/testing to lib/testing/src. Moved top level testing files from lib/ to lib/testing.
Added top level runtime file.
Fixed checked_mode comment, added testing/all_tests comment.
Merge pull request #30 from davidmorgan/add-base-checked-mode

Add "base" library. Add checked mode tester.
Add Optional type and test to collection library.
shuffle a list
Merge pull request #37 from sethladd/shuffle-list

shuffle a list
fix enumerate to correctly iterate more than once
add tests
remove shuffle, it was just added to the core sdk
fix type annotations
Removed upper bounds on SDK dependencies
Merge pull request #41 from sethladd/remove-shuffle

remove shuffle, it was just added to the core sdk
Merge pull request #42 from cbracken/sdk-upper-bound

Removed upper bounds on SDK dependencies
Merge pull request #39 from google/fix_enumerate

fix enumerate to correctly iterate more than once
Fix warnings.
Add shuffle to List implementations.
Bump version
Update testing library names.