Make test pytest compatible

MANIFEST.in

@@ -3,3 +3,4 @@ recursive-include pylatex *.py
 recursive-include python2_source/pylatex *.py
 include versioneer.py
 include examples/kitten.jpg
+include examples/sample-logo.png

tests/test_tabular.py

@@ -1,11 +1,12 @@
 #!/usr/bin/env python
+import os.path as osp
 
 from pylatex import Document, MultiColumn, Section, StandAloneGraphic, Tabular
 
 # This file contains function that test several Tabular related functionality.
 
 
-def test_tabular_can_add_row_passing_many_arguments(sample_logo_path):
+def test_tabular_can_add_row_passing_many_arguments():
     """
     Test that Tabular can add a row as described in the function body:
     The first method is to pass the content of each cell as a separate argument.
@@ -16,6 +17,7 @@ def test_tabular_can_add_row_passing_many_arguments(sample_logo_path):
 
     """
     doc = Document()
+    sample_logo_path = osp.join(__file__[0:-15], "..", "examples", "sample-logo.png")
 
     with doc.create(Section("Can Add Row Passing Many Arguments")):
         with doc.create(Tabular("|c|c|", booktabs=True)) as table:
@@ -30,7 +32,7 @@ def test_tabular_can_add_row_passing_many_arguments(sample_logo_path):
     doc.generate_pdf(clean_tex=False)
 
 
-def test_tabular_can_add_row_passing_iterable(sample_logo_path):
+def test_tabular_can_add_row_passing_iterable():
     """
     Test that Tabular can add a row as described in the function body:
     The second method
@@ -44,6 +46,7 @@ def test_tabular_can_add_row_passing_iterable(sample_logo_path):
     """
     doc = Document()
 
+    sample_logo_path = osp.join(__file__[0:-15], "..", "examples", "sample-logo.png")
     with doc.create(Section("Can Add Row Passing Iterable")):
         with doc.create(Tabular("|c|c|", booktabs=True)) as table:
             multi_columns_array = [
@@ -57,14 +60,3 @@ def test_tabular_can_add_row_passing_iterable(sample_logo_path):
 
             table.add_row(multi_columns_array)
     doc.generate_pdf()
-
-
-if __name__ == "__main__":
-    import os.path as osp
-
-    sample_logo_path = osp.abspath(
-        osp.join(__file__[0:-15], "..", "examples", "sample-logo.png")
-    )
-
-    test_tabular_can_add_row_passing_many_arguments(sample_logo_path=sample_logo_path)
-    test_tabular_can_add_row_passing_iterable(sample_logo_path=sample_logo_path)