Building with Python 3.6

[mingodad]

Trying to build this project on Ubuntu 18.04 that has Python 3.6 I did this small change and got it to build:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6173963f..362fccc66 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -175,7 +175,7 @@ if (SOUFFLE_SWIG_PYTHON OR SOUFFLE_SWIG_JAVA)
     find_package(SWIG REQUIRED)
 
     if (SOUFFLE_SWIG_PYTHON)
-        find_package(Python3 3.7 REQUIRED)
+        find_package(Python3 3.6 REQUIRED)
     endif()
 
     if (SOUFFLE_SWIG_JAVA)
@@ -364,7 +364,7 @@ endif(SOUFFLE_CODE_COVERAGE AND CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
 add_subdirectory(src)
 
 if (SOUFFLE_ENABLE_TESTING)
-    find_package(Python3 3.7 REQUIRED)
+    find_package(Python3 3.6 REQUIRED)
     add_subdirectory(src/tests)
     add_subdirectory(tests)
 endif()
diff --git a/src/souffle-compile.template.py b/src/souffle-compile.template.py
index 48ee3046e..d63e384e6 100644
--- a/src/souffle-compile.template.py
+++ b/src/souffle-compile.template.py
@@ -41,7 +41,8 @@ import tempfile
 def launch_command(cmd, descr, verbose=False):
     if verbose:
         sys.stdout.write(cmd + "\n")
-    status = subprocess.run(cmd, capture_output=True, text=True, shell=True)
+    #status = subprocess.run(cmd, capture_output=True, text=True, shell=True)
+    status = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
     if status.returncode != 0:
         sys.stdout.write(status.stdout)
         sys.stderr.write(status.stderr)

It seems that the need for Python 3.7 is easy to be lowered.