path errors in some tests fixed

CHANGES.txt

+DHParser Version 0.8.1 (2.7.2018)
+.................................
+
+- compatibility fixes for Python 3.7
+
+
 DHParser Version 0.8.0 (24.6.2018)
 ..................................
 

DHParser/versionnumber.py

@@ -16,4 +16,4 @@
 # permissions and limitations under the License.
 
 __all__ = ('__version__',)
-__version__ = '0.8.0' # + '_dev' + str(os.stat(__file__).st_mtime)
+__version__ = '0.8.1' # + '_dev' + str(os.stat(__file__).st_mtime)

test/test_compile.py

@@ -19,6 +19,9 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import sys
+
+sys.path.extend(['../', './'])
 
 from DHParser import parse_sxpr, Compiler
 

test/test_error.py

@@ -20,6 +20,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import sys
+
+sys.path.extend(['../', './'])
+
 try:
     import regex as re
 except ImportError:

test/test_preprocess.py

@@ -19,8 +19,9 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
-# import sys
-# sys.path.append('../')
+import sys
+
+sys.path.extend(['../', './'])
 
 from functools import partial