Include and update tests for BetaBinomial (#1578)

Author: devmotion

test/betabinomial.jl

@@ -2,12 +2,12 @@ using Distributions
 using Test
 
 @testset "Log of Beta-binomial distribution" begin
-    d = BetaBinomial(50, 0.2,0.6)
+    d = BetaBinomial(50, 0.2, 0.6)
 
-    for k in Base.OneTo(50)
+    for k in 1:50
         p  = pdf(d, k)
         lp = logpdf(d, k)
-        @test_approx_eq lp log(p)
+        @test lp ≈ log(p)
         @test insupport(d, k)
     end
     @test !insupport(d, 51)

test/runtests.jl

@@ -37,6 +37,7 @@ const tests = [
     "fit",
     "multinomial",
     "binomial",
+    "betabinomial",
     "poissonbinomial",
     "dirichlet",
     "dirichletmultinomial",