Documentation updates for testing information (#1293)

- Removes references to 'runtests.sh', as it has been removed
- Adds links from the contributing file to the readme - testing section
- Updates flake8 stats

.flake8

@@ -1,17 +1,17 @@
 # Some PEP8 deviations are considered irrelevant to stub files:
-# (error counts as of 2016-12-19)
-# 17381 E704 multiple statements on one line (def)
-# 11840 E301 expected 1 blank line
-#  7467 E302 expected 2 blank lines
-#  1772 E501 line too long
-#  1487 F401 imported but unused
-#  1248 E701 multiple statements on one line (colon)
-#   427 F811 redefinition
-#   356 E305 expected 2 blank lines
+# (error counts as of 2017-05-22)
+# 17952 E704 multiple statements on one line (def)
+# 12197 E301 expected 1 blank line
+#  7155 E302 expected 2 blank lines
+#  2307 E501 line too long
+#  1463 F401 imported but unused
+#   967 E701 multiple statements on one line (colon)
+#   457 F811 redefinition
+#   390 E305 expected 2 blank lines
 
 # Nice-to-haves ignored for now
-#   152 E128 continuation line under-indented for visual indent
-#    43 E127 continuation line over-indented for visual indent
+#   159 E128 continuation line under-indented for visual indent
+#    34 E127 continuation line over-indented for visual indent
 
 [flake8]
 ignore = F401, F811, E127, E128, E301, E302, E305, E501, E701, E704, B303