tests: move/rename/cleanup vspec based tests (#860)

The main motivation is to being able to use normal/other pytest based
tests.

Therefore this moves everything from conftest into test_integration
itself.

test/vspec/pyimport.vim

@@ -0,0 +1,35 @@
+source plugin/jedi.vim
+source test/_utils.vim
+
+describe 'pyimport'
+    before
+        let g:jedi#use_tabs_not_buffers = 1
+    end
+
+    after
+        try | %bwipeout! | catch | endtry
+    end
+
+    it 'open_tab'
+        Pyimport os 
+        Expect CurrentBufferIsModule('os') == 1
+        Pyimport subprocess 
+        Expect CurrentBufferIsModule('subprocess') == 1
+        " the empty tab is sometimes also a tab
+        Expect tabpagenr('$') >= 2
+    end
+
+    it 'completion'
+        " don't know how to test this directly
+        "execute "Pyimport subproc\<Tab>"
+        "Expect CurrentBufferIsModule('subprocess') == 1
+
+        Expect jedi#py_import_completions('subproc', 0, 0) == 'subprocess'
+        Expect jedi#py_import_completions('subprocess', 0, 0) == 'subprocess'
+        let g:comp = jedi#py_import_completions('zip', 0, 0)
+        " Sometimes zipapp is in there sometimes not, depends on Python
+        " version.
+        let g:comp = substitute(g:comp, '^zipapp\n', '', '')
+        Expect g:comp == "zipfile\nzipimport"
+    end
+end