Failure in Vizier with Python 3

With Python 3, I get:

```
In [3]: Vizier.query_region("AFGL 2591", radius='0d5m', catalog="B/iram/pdbi")
Traceback (most recent call last):
  File "/Users/tom/Library/Python/3.3/lib/python/site-packages/astroquery-0.0.dev998-py3.3.egg/astroquery/vizier/core.py", line 526, in _parse_result
    tf.write(response.content.encode('utf-8'))
AttributeError: 'bytes' object has no attribute 'encode'
WARNING: Error in parsing result, returning raw result instead [astroquery.vizier.core]
Out[3]: b'<?xml version="1.0" encoding="UTF-8"?>\n<VOTABLE version="1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"\n  xmlns="http://www.ivoa.net/xml/VOTable/v1.2"\n  xsi:schemaLocation="http://www.ivoa.net/xml/VOTable/v1.2 http://www.ivoa.net/xml/VOTable/v1.2">\n <DESCRIPTION>\n   VizieR Astronomical Server vizier.u-strasbg.fr\n    Date: 2013-08-13T18:28:24 [V1.97 (28-Nov-2012)]\n   Explanations and Statistics of UCDs:\t\t\tSee LINK below\n   In case of problem, please report to:\tquestion@simbad.u-strasbg.fr\n </DESCRIPTION>\n<!-- VOTable description at http://www.ivoa.net/Documents/latest/VOT.html -->\n<INFO ID="VERSION" name="votable-version" value="1.97 (28-Nov-2012)"/>\n<INFO ID="Ref" name="-ref" value="VOTx26274"/>\n<INFO ID="MaxTuples" name="-out.max" value="50"/>\n<INFO name="queryParameters" value="6">\n-oc.form=D.\n-source=B/iram/pdbi\n-c=307.353875+40.188583\n-c.rd=0.08333333333333333\n-out=*\n-out.max=50\n</INFO>\n\n<!--\nExecution Reports\n -->\n<INFO ID="Target" name="-c" value="307.353875+40.188583,rd=0.083333">\n</INFO>\n\n<RESOURCE ID="yCat_102016" name="B/iram">\n  <DESCRIPTION>IRAM Observation Logs (IRAM 1991-2013)</DESCRIPTION>\n  <COOSYS ID="J2000" system="eq_FK5" equinox="J2000"/>\n  <TABLE ID="B_iram_pdbi" name="B/iram/pdbi">\n    <DESCRIPTION>The Plateau de Bure Interferometer Observation Log between 1991-12-01 and 2012-03-31</DESCRIPTION>\n    <!-- Definitions of GROUPs and FIELDs -->\n    <FIELD name="Prog" ucd="meta.code;obs" datatype="char" arraysize="4"><!-- ucd="OBS_CODE" -->\n      <DESCRIPTION>Identification code of the program</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Name" ucd="meta.id" datatype="char" arraysize="12*"><!-- ucd="ID_TARGET" -->\n      <DESCRIPTION>Source name, as mentioned in the observing program</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Obs" ucd="time.start;obs" datatype="char" arraysize="10" unit="&quot;Y:M:D&quot;"><!-- ucd="TIME_DATE" -->\n      <DESCRIPTION>Starting date of the Observation (5)</DESCRIPTION>\n    </FIELD>\n    <FIELD name="tos" ucd="time.expo" datatype="int" width="6" unit="s"><!-- ucd="TIME_EXPTIME" -->\n      <DESCRIPTION>Total on-source correlation time</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Type" ucd="instr.setup" datatype="char" arraysize="3"><!-- ucd="INST_SETUP" -->\n      <DESCRIPTION>Program type (1)</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Vel" ucd="spect.dopplerVeloc" datatype="float" width="6" precision="1" unit="km/s"><!-- ucd="INST_VELOC_CENTRAL" -->\n      <DESCRIPTION>Velocity of the source (3)</DESCRIPTION>\n    </FIELD>\n    <FIELD name="n_Vel" ucd="meta.note" datatype="char" arraysize="1"><!-- ucd="NOTE" -->\n      <DESCRIPTION>[LH] LSR or Heliocentric velocity</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Flow" ucd="em.freq" datatype="int" width="6" unit="MHz"><!-- ucd="OBS_FREQUENCY" -->\n      <DESCRIPTION>? Sky Frequency of the 3mm receiver (6)</DESCRIPTION>\n      <VALUES null="-2147483648" />\n    </FIELD>\n    <FIELD name="n_Flow" ucd="meta.note" datatype="char" arraysize="1"><!-- ucd="NOTE" -->\n      <DESCRIPTION>[UL] Signal Upper/Lower band of the 3mm receiver</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Fhigh" ucd="em.freq" datatype="int" width="6" unit="MHz"><!-- ucd="OBS_FREQUENCY" -->\n      <DESCRIPTION>? Sky Frequency of the 1mm receiver (6)</DESCRIPTION>\n      <VALUES null="-2147483648" />\n    </FIELD>\n    <FIELD name="n_Fhigh" ucd="meta.note" datatype="char" arraysize="1"><!-- ucd="NOTE" -->\n      <DESCRIPTION>[UL] Signal Upper/Lower band of the 1mm receiver</DESCRIPTION>\n    </FIELD>\n    <FIELD name="Conf" ucd="meta.id;instr" datatype="char" arraysize="3"><!-- ucd="INST_ID" -->\n      <DESCRIPTION>Configuration code of the interferometer</DESCRIPTION>\n    </FIELD>\n    <FIELD name="RAJ2000" ucd="pos.eq.ra;meta.main" ref="J2000" datatype="char" arraysize="11" unit="&quot;h:m:s&quot;"><!-- ucd="POS_EQ_RA_MAIN" -->\n      <DESCRIPTION>? Right Ascension J2000</DESCRIPTION>\n      <VALUES null=" " />\n    </FIELD>\n    <FIELD name="DEJ2000" ucd="pos.eq.dec;meta.main" ref="J2000" datatype="char" arraysize="11" unit="&quot;d:m:s&quot;"><!-- ucd="POS_EQ_DEC_MAIN" -->\n      <DESCRIPTION>? Declination J2000</DESCRIPTION>\n      <VALUES null=" " />\n    </FIELD>\n<DATA><TABLEDATA>\n<TR><TD>N032</TD><TD>AFGL2591</TD><TD>2003-12-06</TD><TD>16800</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Cp</TD><TD>20:29:24.87</TD><TD>+40:11:19.8</TD></TR>\n<TR><TD>N032</TD><TD>AFGL2591</TD><TD>2004-05-15</TD><TD>1140</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Dp</TD><TD>20:29:24.87</TD><TD>+40:11:19.8</TD></TR>\n<TR><TD>N032</TD><TD>AFGL2591</TD><TD>2004-05-15</TD><TD>7740</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Dp</TD><TD>20:29:24.87</TD><TD>+40:11:19.8</TD></TR>\n<TR><TD>N032</TD><TD>AFGL2591</TD><TD>2004-05-16</TD><TD>24060</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Dp</TD><TD>20:29:24.87</TD><TD>+40:11:19.8</TD></TR>\n<TR><TD>N032</TD><TD>AFGL2591</TD><TD>2004-05-17</TD><TD>3060</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Dp</TD><TD>20:29:24.87</TD><TD>+40:11:19.8</TD></TR>\n<TR><TD>PB3F</TD><TD>AFGL2591</TD><TD>2005-12-25</TD><TD>4050</TD><TD>MAP</TD><TD>0.0</TD><TD>L</TD><TD>86610</TD><TD>L</TD><TD>230538</TD><TD>L</TD><TD>6Cq</TD><TD>20:29:24.80</TD><TD>+40:11:19.0</TD></TR>\n<TR><TD>PB3F</TD><TD>AFGL2591</TD><TD>2005-12-26</TD><TD>4050</TD><TD>MAP</TD><TD>0.0</TD><TD>L</TD><TD>86610</TD><TD>L</TD><TD>230538</TD><TD>L</TD><TD>6Cq</TD><TD>20:29:24.80</TD><TD>+40:11:19.0</TD></TR>\n<TR><TD>P04A</TD><TD>AFGL2591</TD><TD>2006-02-03</TD><TD>9000</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80578</TD><TD>L</TD><TD>203407</TD><TD>L</TD><TD>6Aq</TD><TD>20:29:24.87</TD><TD>+40:11:19.5</TD></TR>\n<TR><TD>PB3F</TD><TD>AFGL2591</TD><TD>2006-06-03</TD><TD>675</TD><TD>MAP</TD><TD>0.0</TD><TD>L</TD><TD>86610</TD><TD>L</TD><TD>230538</TD><TD>L</TD><TD>5Dq</TD><TD>20:29:24.80</TD><TD>+40:11:19.0</TD></TR>\n<TR><TD>PB3F</TD><TD>AFGL2591</TD><TD>2006-06-04</TD><TD>7425</TD><TD>MAP</TD><TD>0.0</TD><TD>L</TD><TD>86610</TD><TD>L</TD><TD>230538</TD><TD>L</TD><TD>5Dq</TD><TD>20:29:24.80</TD><TD>+40:11:19.0</TD></TR>\n<TR><TD>PB4A</TD><TD>AFGL2591</TD><TD>2007-02-19</TD><TD>9450</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>80126</TD><TD>L</TD><TD>81030</TD><TD>L</TD><TD>6Aq</TD><TD>20:29:24.87</TD><TD>+40:11:19.5</TD></TR>\n<TR><TD>PA4A</TD><TD>AFGL2591</TD><TD>2007-03-04</TD><TD>10800</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>203055</TD><TD>L</TD><TD>203739</TD><TD>L</TD><TD>6Aq</TD><TD>20:29:24.87</TD><TD>+40:11:19.5</TD></TR>\n<TR><TD>PA4A</TD><TD>AFGL2591</TD><TD>2007-03-13</TD><TD>10935</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>203055</TD><TD>L</TD><TD>203739</TD><TD>L</TD><TD>6Bq</TD><TD>20:29:24.87</TD><TD>+40:11:19.5</TD></TR>\n<TR><TD>PA4A</TD><TD>AFGL2591</TD><TD>2007-03-15</TD><TD>9450</TD><TD>MAP</TD><TD>-5.5</TD><TD>L</TD><TD>203055</TD><TD>L</TD><TD>203739</TD><TD>L</TD><TD>6Bq</TD><TD>20:29:24.87</TD><TD>+40:11:19.5</TD></TR>\n</TABLEDATA></DATA>\n</TABLE>\n</RESOURCE>\n</VOTABLE>\n'
```