fixed contig mode filetype detection and implemeted first unit pytests

.github/workflows/github-actions.yaml

@@ -29,7 +29,7 @@ jobs:
         sudo apt-get install ncbi-blast+ clustalw -y
         sudo apt-get install python3-pip python3-numpy python3-pandas -y
         python3 -m pip install --upgrade pip setuptools
-        pip3 install pytest "biopython>=>=1.7,<1.78"
+        pip3 install pytest "biopython>=1.7,<1.78"
         if [ -f requirements.txt ]; then 
           pip3 install -r requirements.txt;
         else