implement binary search tree in Go
Clojure ETL full-dataset test incorrectly removes first element

The form of the test data uses a subvec with an index of 1:
(subvec (clojure.string/split "AEIOULNRST" #"") 1)
That removes the first element from the list so "A" is lost and
the current example fails that test. Fix it so the initial letter
is not removed and example is correct for test.

Signed-off-by: Geoff Lane <geoff@zorched.net>
DNA strands should only contain valid nucleotides

Extra Clojure test case for rna-transcription
Merge pull request #1143 from geofflane/clojure-etl-off-by-one

Clojure ETL full-dataset test incorrectly removes first element
Merge pull request #1146 from solaryeti/validate_dna_strand

DNA strands should only contain valid nucleotides
Remove code in support of 'tweaked' submission state
Add palindrome products exercise for elixir
Merge pull request #1152 from petehuang/add-palindrome-products-elixir

Add palindrome products exercise for elixir
Move demo code into handler.

I am slowly introducing duplication because the abstractions don't
seem to be right, and duplication might let me see what the actual
abstractions that I need are.
Allow team owner to destroy their team
Reformat go test fixtures
Reformat go assignments
Correctly set the team slug if name is empty
Adding unique index on team slug.
A validation at the model level might not be enough to prevent duplicate records in the db. Adding unique index fixes this case.
Re-approve api tests
Merge pull request #1155 from Tonkpils/fix-possible-race-condition

Adding unique index on team slug.
Merge pull request #1154 from Tonkpils/fix-empty-name

Correctly set the team slug if name is empty
Merge pull request #1153 from Tonkpils/destroy-team

Allow team owner to destroy their team
Delete dependency in demo test
Expand fake curricula