ensure uncertainties does not depend on numpy

fix import ordering to ensure that uncertainties can be used without
numpy, before this the check assumed that numpy was always installed

update test_issue1611 to use requires_numpy since uncertainties and
numpy are now decoupled

pint/compat.py

@@ -75,7 +75,8 @@ class BehaviorChangeWarning(UserWarning):
 
 try:
     from uncertainties import UFloat, ufloat
-    from uncertainties import unumpy as unp
+
+    unp = None
 
     HAS_UNCERTAINTIES = True
 except ImportError:
@@ -92,6 +93,8 @@ class BehaviorChangeWarning(UserWarning):
     HAS_NUMPY = True
     NUMPY_VER = np.__version__
     if HAS_UNCERTAINTIES:
+        from uncertainties import unumpy as unp
+
         NUMERIC_TYPES = (Number, Decimal, ndarray, np.number, UFloat)
     else:
         NUMERIC_TYPES = (Number, Decimal, ndarray, np.number)

pint/testsuite/test_issues.py

@@ -922,6 +922,7 @@ def test_issue_1400(self, sess_registry):
         assert q2.format_babel("~", locale="es_ES") == "3,1 W/cm"
         assert q2.format_babel("", locale="es_ES") == "3,1 vatios por centímetro"
 
+    @helpers.requires_numpy()
     @helpers.requires_uncertainties()
     def test_issue1611(self, module_registry):
         from numpy.testing import assert_almost_equal