Add converse tests and example

Author: jamesnohilly

src/Groups/group_constructors.jl

@@ -863,7 +863,7 @@ of order $2^{k+1}, k \geq 2$, and `false` otherwise.
 julia> is_quaternion_group(small_group(8, 3))
 false
 
-julia> is_quaternion_group(small_group(8, 4))
+julia> is_quaternion_group(transitive_group(8, 5))
 true
 ```
 """

test/Groups/constructors.jl

@@ -65,7 +65,10 @@ end
   @test isa(dihedral_group(PermGroup, 6), PermGroup)
 
   @test is_quaternion_group(small_group(8, 4))
+  @test ! is_quaternion_group(small_group(12, 3))
   @test is_dicyclic_group(small_group(8, 4))
+  @test ! is_dicyclic_group(small_group(13, 1))
+
   @test small_group_identification(small_group(8, 4)) == (8, 4)
   @test isa(small_group(8, 4), PcGroup)
   @test isa(small_group(60, 5), PermGroup)