Checkout target deployment destination (#116)

* Checkout target deployment destination
* Init git repository with intended branch
* Create branch if it doesn't exist
* Add test master branch switch

Author: schrismartin

Sources/Publish/API/DeploymentMethod.swift

@@ -59,6 +59,11 @@ public extension DeploymentMethod {
                     at: folder.path
                 )
 
+                try shellOut(
+                    to: "git checkout \(branch) || git checkout -b \(branch)",
+                    at: folder.path
+                )
+
                 try folder.empty()
             }
 

Tests/PublishTests/Tests/DeploymentTests.swift

@@ -62,6 +62,8 @@ final class DeploymentTests: PublishTestCase {
 
         try shellOut(to: [
             "git init",
+            // Not all git installations init with a master branch.
+            "git checkout master || git checkout -b master",
             "git config --local receive.denyCurrentBranch updateInstead"
         ], at: remote.path)
 
@@ -86,7 +88,14 @@ final class DeploymentTests: PublishTestCase {
         let remote = try container.createSubfolder(named: "Remote.git")
         let repo = try container.createSubfolder(named: "Repo")
 
-        try shellOut(to: .gitInit(), at: remote.path)
+        try shellOut(
+          to: [
+            "git init",
+            // Not all git installations init with a master branch.
+            "git checkout master || git checkout -b master"
+          ],
+          at: remote.path
+        )
 
         // First generate
         try publishWebsite(in: repo, using: [