add simple unit tests for SizedArray inner constructors

Per request on PR #151. I'm not familiar with this codebase so this may not be the ideal unit test
or the ideal location, but I've tried to follow local convention.

Author: gostevehoward

test/SizedArray.jl

@@ -0,0 +1,15 @@
+@testset "SizedArray" begin
+    @testset "Inner Constructors" begin
+        @test SizedArray{Tuple{2}, Int, 1}([3, 4]).data == [3, 4]
+        @test SizedArray{Tuple{2, 2}, Int, 2}(collect(3:6)).data == collect(3:6)
+        @test size(SizedArray{Tuple{4, 5}, Int, 2}().data) == (4, 5)
+        @test size(SizedArray{Tuple{4, 5}, Int}().data) == (4, 5)
+
+        # Bad input
+        @test_throws Exception SArray{Tuple{1},Int,1}([2 3])
+
+        # Bad parameters
+        @test_throws Exception SizedArray{Tuple{1},Int,2}()
+        @test_throws Exception SArray{Tuple{3, 4},Int,1}()
+    end
+end

test/runtests.jl

@@ -11,6 +11,7 @@ using Base.Test
     include("FieldVector.jl")
     include("Scalar.jl")
     include("SUnitRange.jl")
+    include("SizedArray.jl")
     include("custom_types.jl")
 
     include("core.jl")