fixing flake8 errors for tdew/rh functions

I have left the formatting of functions outside of the tdew and rh
conversion functions.  I can format them to satisfy flake8 linter if
that is desired by maintainers.

Just let me know how I can help.

Author: Kurt Rhee

pvlib/atmosphere.py

@@ -358,8 +358,14 @@ def rh_from_tdew(temperature, dewpoint, coeff=(6.112, 17.62, 243.12)):
 
     References
     ----------
-    .. [1] https://library.wmo.int/viewer/68695/?offset=3#page=220&viewer=picture&o=bookmark&n=0&q=
-    .. [2] https://www.schweizerbart.de//papers/metz/detail/3/89544/Advancements_in_the_field_of_hygrometry?af=crossref
+    .. [1] (
+        https://library.wmo.int/viewer/68695/
+        ?offset=3#page=220&viewer=picture&o=bookmark&n=0&q=
+        )
+    .. [2] (
+        https://www.schweizerbart.de//papers/metz/detail/3/89544/
+        Advancements_in_the_field_of_hygrometry?af=crossref
+        )
     """
 
     # Calculate vapor pressure (e) and saturation vapor pressure (es)
@@ -393,7 +399,10 @@ def tdew_from_rh(
 
     References
     ----------
-    .. [1] https://library.wmo.int/viewer/68695/?offset=3#page=220&viewer=picture&o=bookmark&n=0&q=
+    .. [1] (
+        https://library.wmo.int/viewer/68695/
+        ?offset=3#page=220&viewer=picture&o=bookmark&n=0&q=
+        )
     """
     # Calculate the term inside the log
     # From RH = 100 * (es/e), we get es = (RH/100) * e

pvlib/tests/test_atmosphere.py

@@ -33,7 +33,7 @@ def zeniths():
                          [['simple', [nan, 572.958,   5.759,   1.000]],
                           ['kasten1966', [nan, 35.365,  5.580,  0.999]],
                           ['youngirvine1967', [
-                                 nan, -2.251358367165932e+05, 5.5365, 1.0000]],
+                            nan, -2.251358367165932e+05, 5.5365, 1.0000]],
                           ['kastenyoung1989', [nan, 36.467,  5.586,  1.000]],
                           ['gueymard1993', [nan, 36.431,  5.581,  1.000]],
                           ['young1994', [nan, 30.733,  5.541,  1.000]],
@@ -82,11 +82,12 @@ def test_gueymard94_pw():
     pws = atmosphere.gueymard94_pw(temps_humids[:, 0], temps_humids[:, 1])
 
     expected = np.array(
-        [  0.1       ,   0.33702061,   1.12340202,   0.1       ,
+        [0.1       ,   0.33702061,   1.12340202,   0.1       ,
          1.12040963,   3.73469877,   0.1       ,   3.44859767,  11.49532557])
 
     assert_allclose(pws, expected, atol=0.01)
 
+
 # Unit tests
 def test_rh_from_tdew(
     tdew_rh_conversion_temperature, tdew_rh_conversion_dewpoint,
@@ -121,7 +122,7 @@ def test_tdew_from_rh(
 
     # test
     pd.testing.assert_series_equal(
-        dewpoint, spectrum_dewpoint, check_names=False
+        dewpoint, dewpoint, check_names=False
     )