Problem with the test battery Python 2.x

[SeBecker]

______________________________ ERROR collecting  _______________________________
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/py/_path/common.py:377: in visit
    for x in Visitor(fil, rec, ignore, bf, sort).gen(self):
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/py/_path/common.py:429: in gen
    for p in self.gen(subdir):
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/py/_path/common.py:419: in gen
    if p.check(dir=1) and (rec is None or rec(p))])
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/_pytest/main.py:728: in _recurse
    ihook = self.gethookproxy(path)
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/_pytest/main.py:632: in gethookproxy
    my_conftestmodules = pm._getconftestmodules(fspath)
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/_pytest/config.py:356: in _getconftestmodules
    mod = self._importconftest(conftestpath)
../../../virtualenv/python2.7.14/lib/python2.7/site-packages/_pytest/config.py:381: in _importconftest
    raise ConftestImportFailure(conftestpath, sys.exc_info())
E   ConftestImportFailure: ImportError('cannot import name isclose',)
E     File "/home/travis/build/OpenSourceEconomics/grmpy/grmpy/__init__.py", line 6, in <module>
E       from grmpy.simulate.simulate import simulate
E     File "/home/travis/build/OpenSourceEconomics/grmpy/grmpy/simulate/simulate.py", line 6, in <module>
E       from grmpy.estimate.estimate_auxiliary import calculate_criteria
E     File "/home/travis/build/OpenSourceEconomics/grmpy/grmpy/estimate/estimate_auxiliary.py", line 12, in <module>
E       from grmpy.check.check import UserError
E     File "/home/travis/build/OpenSourceEconomics/grmpy/grmpy/check/check.py", line 6, in <module>
E       from math import isclose
!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!
=========================== 1 error in 1.58 seconds ============================

I think there is a problem with the isclose import in check.py. Please fix it.

[SeBecker]

This is fixed in Benedikt's branch.