Fix IMFV283Parser test

test/imfv283_test/IMFV283Parser_test.py

 """Tests for the IMFV283 Parser class."""
+from __future__ import unicode_literals
+from builtins import str
 
 from nose.tools import assert_equals
 from obspy import UTCDateTime
@@ -6,15 +8,15 @@ from obspy import UTCDateTime
 from geomagio.imfv283 import IMFV283Parser, imfv283_codes
 
 
-IMFV283_EXAMPLE_VIC = '75C2A3A814023012741G43-1NN027EUP00191`A^P@RVxZ}|' + \
-    'D@@B_BEM@@@@@@@@@@@@@@@@@@@@@@@@@@@E|BxtTADVD@\\E\\BxxT@tVCh\\E' + \
-    'lByDT@xVCp\\EdBy@T@tVCh\\EhByPT@xVCl\\EPBy@T@tVCd\\EdBxlTA@VCp\\Eh' + \
-    'BxTTA@VCp\\EdBGxTA@VCl\\EPBG`T@xVC\\\\DtBGHT@lVCD\\DPBG@T@XVBh\\'
+IMFV283_EXAMPLE_VIC = b'75C2A3A814023012741G43-1NN027EUP00191`A^P@RVxZ}|' + \
+    b'D@@B_BEM@@@@@@@@@@@@@@@@@@@@@@@@@@@E|BxtTADVD@\\E\\BxxT@tVCh\\E' + \
+    b'lByDT@xVCp\\EdBy@T@tVCh\\EhByPT@xVCl\\EPBy@T@tVCd\\EdBxlTA@VCp\\Eh' + \
+    b'BxTTA@VCp\\EdBGxTA@VCl\\EPBG`T@xVC\\\\DtBGHT@lVCD\\DPBG@T@XVBh\\'
 
-IMFV283_EXAMPLE_FRD = '75C2102614023012927G43-0NN027EUP00191bx@WyhD{' + \
-    'aDB~@X@{Bb@@@@@@@@@@@@@@@@@@@@@@@@@@@@[DAV[@cUAjT@[EAVZ@cUAjT@[' + \
-    'BAVZ@cVAjS@[DAVZ@cUAjS@[DAVZ@cUAjS@[GAV\\@cTAjT@[DAV[@cUAjT@[BAVY' + \
-    '@cVAjT@[CAVW@cWAjT@[CAVT@cWAjU@[AAVO@cYAjV@Z}AVK@c[AjV'
+IMFV283_EXAMPLE_FRD = b'75C2102614023012927G43-0NN027EUP00191bx@WyhD{' + \
+    b'aDB~@X@{Bb@@@@@@@@@@@@@@@@@@@@@@@@@@@@[DAV[@cUAjT@[EAVZ@cUAjT@[' + \
+    b'BAVZ@cVAjS@[DAVZ@cUAjS@[DAVZ@cUAjS@[GAV\\@cTAjT@[DAV[@cUAjT@[BAVY' + \
+    b'@cVAjT@[CAVW@cWAjT@[CAVT@cWAjU@[AAVO@cYAjV@Z}AVK@c[AjV'
 
 
 def test_parse_msg_header():
@@ -44,7 +46,7 @@ def test_estimate_data_time__correct_doy():
     """
     parser = IMFV283Parser()
     # BOU aka normal
-    transmission = '17274013121'
+    transmission = b'17274013121'
     day = 274
     minute = 72
     (data_time, transmit_time, corrected) = \
@@ -61,7 +63,7 @@ def test_estimate_data_time__incorrect_doy():
     """
     parser = IMFV283Parser()
     # BLC aka 1999 rollover gps issue
-    transmission = '17274013241'
+    transmission = b'17274013241'
     day = 46
     minute = 78
     (data_time, transmit_time, corrected) = \