rename api-test.pl to .t so it runs under yath

Dependencies

• [2] 2JJP7673 tests: move to t, allow `yath test` from root
• [3] ASPD4MDN Passwords: check in constant time
• [4] MQLCUSZL Test the fake derivations channel, asserting nested packages are properly represented.
• [5] 4Y3LBQYI Use system-features from the Nix conf in the default machine file
• [6] 5DXGOH6Q statsd: add a chance to set hostname and port in hydra.conf
• [7] LZVO64YG Merge in the first bits of the API work
• [8] HWGFAF2B queue runner: test notifications
• [9] GD5IRH26 move the api-test.nix in to the jobsdir
• [10] DNOLOMX7 hydra-send-stats: add a failing test asserting it can run
• [11] S2KNQCPB NixExprs: extract the `escape` function and test it

Change contents

• file move: api-test.pl (----------) → api-test.t (----------)
  [2.697]

  [3.36450]