Migration downloads individual migration binaries (#134)

* Migration downloads individual migration binaries

When performing a migration after installing a new ipfs version, ipfs-update finds the necessary migrations, downloads the latest version of them from the distribution location, unpacks the executables, and runs the migrations in order.  It uses the code located in go-ipfs/repo/fsrepo/migrations to do this.

Also used go-ipfs/repo/fsrepo/migrations for
- fetching binaries for things other than migrations
- fetching version information about binaries other than migrations
- looking at the current repo version

* Use updated IpfsDir() and CheckIpfsDir() to use migrations lib

* Support "latest" and "beta" versions

* Unexported many fields and functions that were unnecessarily exported

* Changed Install.Run to take a context

* Updated dependencies

* Update travis-ci to use go1.16.x

Co-authored-by: Adin Schmahmann <[email protected]>

.gitignore

@@ -1 +1,2 @@
 ipfs-update
+*~

.travis.yml

@@ -8,7 +8,7 @@ os:
 language: go
 
 go:
-  - "1.13.1"
+  - "1.16.x"
 
 env:
   - TEST_VERBOSE=1

config/config.go

@@ -10,13 +10,3 @@ const CurrentVersionNumber = "1.6.1-dev"
 // It might not be currently available, but it might be later if we
 // add a Makefile and set it as a ldflag in the Makefile.
 var CurrentCommit string
-
-func GetUserAgent() string {
-	ua := CurrentAppName + "/" + CurrentVersionNumber
-
-	if CurrentCommit != "" {
-		ua += "-" + CurrentCommit
-	}
-
-	return ua
-}

go.mod

@@ -1,12 +1,12 @@
 module github.com/ipfs/ipfs-update
 
-go 1.12
+go 1.15
 
 require (
 	github.com/blang/semver v3.5.1+incompatible
-	github.com/coreos/go-semver v0.3.0
-	github.com/ipfs/go-ipfs-api v0.0.2
-	github.com/urfave/cli v1.22.1
+	github.com/ipfs/go-ipfs v0.8.1-0.20210331210551-bb8260abe11b
+	github.com/ipfs/go-ipfs-api v0.2.0
+	github.com/urfave/cli/v2 v2.3.0
 	github.com/whyrusleeping/stump v0.0.0-20160611222256-206f8f13aae1
-	golang.org/x/sys v0.0.0-20191118133127-cf1e2d577169
+	golang.org/x/sys v0.0.0-20210309074719-68d13333faf2
 )