Execute(Address splitting should function as intended):
  AssertEqual ['foo', v:null], ale#lsp#SplitAddress('foo')
  AssertEqual ['foo:', v:null], ale#lsp#SplitAddress('foo:')
  AssertEqual ['foo', v:null], ale#lsp#SplitAddress('foo:0')
  AssertEqual ['foo', 123], ale#lsp#SplitAddress('foo:123')
  AssertEqual ['protocol:/foo:', v:null], ale#lsp#SplitAddress('protocol:/foo:')
  AssertEqual ['protocol:/foo', v:null], ale#lsp#SplitAddress('protocol:/foo:0')
  AssertEqual ['protocol:/foo', 123], ale#lsp#SplitAddress('protocol:/foo:123')
  AssertEqual ['protocol:foo', v:null], ale#lsp#SplitAddress('protocol:foo')