Improving test and converage configuration to switch to pytest

.coveragerc

+[run]
+source=./ltfatpy
+omit = ./ltfatpy/tests/*
+
+[html]
+directory=./build/htmlcov

setup.cfg

 [nosetests]
-#verbosity=1
-where=./ltfatpy
-with-xunit=1
-xunit-file=./build/nosetests.xml
-with-coverage=1
-cover-package=ltfatpy
-cover-erase=1
-cover-html=1
-cover-html-dir=../build/htmlcov
+where = ./ltfatpy
+with-xunit = 1
+xunit-file = ./build/nosetests.xml
+with-coverage = 1
+cover-package = ltfatpy
+cover-erase = 1
+cover-html = 1
+cover-html-dir = ../build/htmlcov
 
-[pytest]
+[tool:pytest]
 # Specifies a minimal pytest version required for running tests.
 minversion = 2.6
 # Specifies the options
-addopts = --resultlog=pytests_results.txt -k "not _old" --cov-report term-missing --cov=ltfatpy
+addopts = --cov-report=html
+          --cov-report=term-missing
+          --cov=ltfatpy
 # Set the directory basename patterns to avoid when recursing for test discovery.
 norecursedirs = .git bin build cmake-modules ltfat_C_kernel sandboxes .settings
-
-[coverage run]
-source=./ltfatpy
-omit = ./ltfatpy/tests/*
-[coverage html]
-directory=../build/htmlcov
-