Change python2.7 to python3 for kkrnano regtests

tests/gitlab-ci/run_kkrnano.yml

@@ -7,7 +7,7 @@ run_kkrnano:intel:Cu1:
     - mkdir -p test_Cu1; cd test_Cu1; ln -s ../* .
     - ls -la
     - ls -la ..
-    - python2.7 ./tests.py Test_copper.test_Cu1_lmax
+    - python3 ./tests.py Test_copper.test_Cu1_lmax
   artifacts:
     paths:
       - source/KKRnano/regtests/test_Cu1
@@ -27,7 +27,7 @@ run_kkrnano:intel:Cu4:
   script:
     - cd source/KKRnano/regtests
     - mkdir -p test_Cu4; cd test_Cu4; ln -s ../* .
-    - python2.7 ./tests.py Test_copper.test_Cu4_lmax
+    - python3 ./tests.py Test_copper.test_Cu4_lmax
   artifacts:
     paths:
       - source/KKRnano/regtests/test_Cu4
@@ -47,7 +47,7 @@ run_kkrnano:intel:GaN:
   script:
     - cd source/KKRnano/regtests
     - mkdir -p test_GaN; cd test_GaN; ln -s ../* .
-    - python2.7 ./tests.py Test_semiconductors.test_GaN
+    - python3 ./tests.py Test_semiconductors.test_GaN
   artifacts:
     paths:
       - source/KKRnano/regtests/test_GaN
@@ -67,7 +67,7 @@ run_kkrnano:intel:Si:
   script:
     - cd source/KKRnano/regtests
     - mkdir -p test_Si; cd test_Si; ln -s ../* .
-    - python2.7 ./tests.py Test_semiconductors.test_Si
+    - python3 ./tests.py Test_semiconductors.test_Si
   artifacts:
     paths:
       - source/KKRnano/regtests/test_Si
@@ -87,7 +87,7 @@ run_kkrnano:intel:ZnO:
   script:
     - cd source/KKRnano/regtests
     - mkdir -p test_ZnO; cd test_ZnO; ln -s ../* .
-    - python2.7 ./tests.py Test_semiconductors.test_ZnO
+    - python3 ./tests.py Test_semiconductors.test_ZnO
   artifacts:
     paths:
       - source/KKRnano/regtests/test_ZnO
@@ -107,7 +107,7 @@ run_kkrnano:intel:MnGeB20:
   script:
     - cd source/KKRnano/regtests
     - mkdir -p test_MnGeB20; cd test_MnGeB20; ln -s ../* .
-    - python2.7 ./tests.py Test_nocosocmaterials.test_MnGeB20
+    - python3 ./tests.py Test_nocosocmaterials.test_MnGeB20
   artifacts:
     paths:
       - source/KKRnano/regtests/test_MnGeB20