implement binary search tree in Go
ruby/clock spec: test wrapping around backwards.
ruby grade-school test: skip all but one test
Merge pull request #1392 from alxndr/ruby_grade-school_test-tweak

add missing `skip` to a ruby grade-school test file
Remove irrelevant instructions from clock exercise
Use UTC to avoid timezone issues in clock example
Allow fetching of next exercise when you have hibernating submissions
Merge pull request #1393 from stevenwu/develop

Allow fetching of next exercise when you have hibernating submissions
Strip trailing whitespace.
Clarify precedence in query
Merge pull request #1390 from henrik/patch-9

ruby/clock spec: test wrapping around backwards.
Ditch accumulate exercise in coffeescript
Revert "Ditch accumulate exercise in coffeescript"

This reverts commit e59d576dd3cf98fb7631972d499df58191d7837a.
Deprecate accumulate in coffeescript
add `skip` to some ruby tests
Merge pull request #1396 from alxndr/ruby-test-tweaks

add `skip` to some ruby tests
Delete left-over code in go/word-count tests
Move type definition into separate file in go/word-count
Improve test suite in go/hamming
Clarify the size of a gigasecond. Fixes #1399