add some basic tests for env interface

Author: rejuvyesh

test/environments.jl

@@ -12,7 +12,9 @@ environments = [
     :block
 ]
 
-for name in environments 
+@testset "$name" for name in environments 
     env = get_environment(name)
-    @test true
+    @test size(reset(env)) == (env.observation_space.n,)
+    o, r, d, i = step(env, Dojo.sample(env.input_space))
+    @test size(o) == (env.observation_space.n,)
 end