always specify upstream when pushing/pulling

test/integration/pullAndSetUpstream/expected_remote/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/master

test/integration/pullAndSetUpstream/expected_remote/config

@@ -0,0 +1,8 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = true
+	ignorecase = true
+	precomposeunicode = true
+[remote "origin"]
+	url = /Users/jesseduffieldduffield/go/src/github.com/jesseduffield/lazygit/test/integration/pullAndSetUpstream/./actual

test/integration/pullAndSetUpstream/expected_remote/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

test/integration/pullAndSetUpstream/expected_remote/info/exclude

@@ -0,0 +1,7 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~
+.DS_Store

test/integration/pullAndSetUpstream/expected_remote/packed-refs

@@ -0,0 +1,2 @@
+# pack-refs with: peeled fully-peeled sorted 
+766e681a51daa75233c1c4ae8845be2c893577d5 refs/heads/master