New remote test failures

The ALMA archive can result in test failures if the data are not staged fast enough:
```
>       assert totalsize.to(u.GB).value > 1
E       assert 0.0 > 1
E        +  where 0.0 = <Quantity 0.0 Gbyte>.value
E        +    where <Quantity 0.0 Gbyte> = <bound method Quantity.to of <Quantity 0.0 Gbyte>>(Unit("Gbyte"))
E        +      where <bound method Quantity.to of <Quantity 0.0 Gbyte>> = <Quantity 0.0 Gbyte>.to
E        +      and   Unit("Gbyte") = u.GB
```

These should not be a concern; they should go away if the tests are run a second time.


IRSA_dust seems to suffer from an upstream change, I think:
```
__________________________________________________________ TestDust.test_get_extinction_table_class ___________________________________________________________

self = <astroquery.irsa_dust.tests.test_irsa_dust_remote.TestDust object at 0x109466190>

    def test_get_extinction_table_class(self):
        table = irsa_dust.core.IrsaDust.get_extinction_table("m51")
        expected_table = Table.read(self.data(M51_EXT_TBL), format='ipac')
>       assert table.meta == expected_table.meta
E       assert OrderedDict([...J2000)'})]))]) == OrderedDict([(...J2000)'})]))])
E         Omitting 1 identical items, use -v to show
E         Differing items:
E         {'keywords': OrderedDict([('Coordinates', {'value': '202.469574803 47.1952580768 (  202.469570000    47.195260000 equ J2000)'})])} != {'keywords': OrderedDict([('Coordinates', {'value': 'm51 (  202.484170000    47.230560000 equ J2000)'})])}

astroquery/irsa_dust/tests/test_irsa_dust_remote.py:130: AssertionError
```

I don't know what to do about this one except maybe re-download the IRSA data.


LAMDA had an update in #405 that broke remote tests; I never adequately checked:
```
______________________________________________________________________ test_query_levels ______________________________________________________________________

    @remote_data
    def test_query_levels():
        result = lamda.query(mol='co', query_type='erg_levels')
>       assert len(result) == 41
E       assert 3 == 41
E        +  where 3 = len(({'OH2': <Table rows=820 names=('Transition','Upper','Lower','C_ij(T=2)','C_ij(T=5)','C...'), ('C_ij(T=1000)', '<f8'),...ight','J')>\narray([(1, 0.0, 1, u'0')...  dtype=[('Level', '<i8'), ('Energy', '<f8'), ('Weight', '<i8'), ('J', '<U2')])))

astroquery/lamda/tests/test_lamda_remote.py:12: AssertionError
_____________________________________________________________________ test_query_radtrans _____________________________________________________________________

    @remote_data
    def test_query_radtrans():
        result = lamda.query(mol='co', query_type='rad_trans')
>       assert len(result) == 40
E       assert 3 == 40
E        +  where 3 = len(({'OH2': <Table rows=820 names=('Transition','Upper','Lower','C_ij(T=2)','C_ij(T=5)','C...'), ('C_ij(T=1000)', '<f8'),...ight','J')>\narray([(1, 0.0, 1, u'0')...  dtype=[('Level', '<i8'), ('Energy', '<f8'), ('Weight', '<i8'), ('J', '<U2')])))

astroquery/lamda/tests/test_lamda_remote.py:18: AssertionError
____________________________________________________________________ test_query_collrates _____________________________________________________________________

    @remote_data
    def test_query_collrates():
        result = lamda.query(mol='co', query_type='coll_rates', coll_partner_index=1)
>       assert len(result) == 820
E       assert 3 == 820
E        +  where 3 = len(({'OH2': <Table rows=820 names=('Transition','Upper','Lower','C_ij(T=2)','C_ij(T=5)','C...'), ('C_ij(T=1000)', '<f8'),...ight','J')>\narray([(1, 0.0, 1, u'0')...  dtype=[('Level', '<i8'), ('Energy', '<f8'), ('Weight', '<i8'), ('J', '<U2')])))

astroquery/lamda/tests/test_lamda_remote.py:24: AssertionError
=========================================== 5 failed, 501 passed, 1 skipped, 2 xfailed, 1 xpassed in 431.39 seconds ===========================================
```