Error in newly initialized git repo.

[Nageswari-droid]

Describe the bug
When a new git repo is added, stage, commit, push operations are not available for these repositories.

To Reproduce
Steps to reproduce the behaviour:

1. Go to repositories
2. Click on the newly initialized git repo
3. Try to stage, commit or push
4. See an error

Expected behaviour
It should have all the basic operations.

Screenshots

Desktop (please complete the following information):

• OS : Windows
• Browser : Chrome
• Version : v2.1.0

Issue Type

mark with [x] to select the check box

• UI Issue
• Performance Issue
• Feature Breaking Issue
• Security Issue

Severity

mark with [x] to select the check box

• Critical (The application crashes / breaks completely)
• High (Blocks you from performing a critical operation)
• Moderate (Bearable or Manageable issue)
• Low (Something is not right, but the impact is minimal)

[Nageswari-droid]

2021/04/20 13:42:19 [WARNING]: Repo has no HEAD. Proceeding with a NIL HEAD
2021/04/20 13:42:19 [ERROR]: goroutine 34 [running]:
runtime/debug.Stack(0xc00009eb78, 0xdb7260, 0xd30f40)
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/runtime/debug/stack.go:24 +0xa5
github.com/neel1996/gitconvex-server/git.CommitStruct.CommitChanges.func1(0x0, 0x0)
        D:/a/gitconvex/gitconvex/git/git_commit_changes.go:41 +0x45
panic(0xdb7260, 0xd30f40)
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/runtime/panic.go:965 +0x1c7
github.com/libgit2/git2go/v31.(*Repository).CreateCommit(0xc0000f2d40, 0xe42bd7, 0x4, 0xc0000f2d80, 0xc0000f2d80, 0xc00017e254, 0xb, 0xc000498660, 0xc00009f090, 0x1, ...)
        C:/Users/runneradmin/go/pkg/mod/github.com/libgit2/git2go/v31@v31.4.10/repository.go:453 +0x142
github.com/neel1996/gitconvex-server/git.CommitStruct.CommitChanges(0xc0000f2d40, 0xc00017e254, 0xb, 0xc00018c420, 0x2f, 0x0, 0x0)
        D:/a/gitconvex/gitconvex/git/git_commit_changes.go:87 +0x2f8
github.com/neel1996/gitconvex-server/graph.(*mutationResolver).CommitChanges(0xc0000d8138, 0xeeed80, 0xc000480cc0, 0xc00017e239, 0x8, 0xc00017e254, 0xb, 0xdb2a60, 0xc000480d20, 0x193ffce05e0, ...)
        D:/a/gitconvex/gitconvex/graph/schema.resolvers.go:265 +0x1da
github.com/neel1996/gitconvex-server/graph/generated.(*executionContext)._Mutation_commitChanges.func2(0xeeed80, 0xc000480cc0, 0x20, 0xdfabc0, 0xc000089601, 0xc0000a6a80)
        D:/a/gitconvex/gitconvex/graph/generated/generated.go:3744 +0x19c
github.com/99designs/gqlgen/graphql/executor.processExtensions.func3(0xeeed80, 0xc000480cc0, 0xc0000a6a80, 0xc000480cf0, 0xc000480d20, 0x0, 0x0)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/executor/extensions.go:62 +0x42
github.com/neel1996/gitconvex-server/graph/generated.(*executionContext)._Mutation_commitChanges(0xc0000895e0, 0xeeed80, 0xc000480c30, 0xc000186880, 0x0, 0x0, 0x0, 0x0, 0x0)
        D:/a/gitconvex/gitconvex/graph/generated/generated.go:3742 +0x2d3
github.com/neel1996/gitconvex-server/graph/generated.(*executionContext)._Mutation(0xc0000895e0, 0xeeed80, 0xc000480c30, 0xc000089370, 0x1, 0x1, 0x193800235a8, 0xc00009f6d8)
        D:/a/gitconvex/gitconvex/graph/generated/generated.go:7101 +0xec6
github.com/neel1996/gitconvex-server/graph/generated.(*executableSchema).Exec.func2(0xeeed80, 0xc000480c00, 0x30)
        D:/a/gitconvex/gitconvex/graph/generated/generated.go:1032 +0x85
github.com/99designs/gqlgen/graphql/executor.(*Executor).DispatchOperation.func1.1.1(0xeeed80, 0xc000480c00, 0xc0000895f0)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/executor/executor.go:105 +0x4a
github.com/99designs/gqlgen/graphql/executor.processExtensions.func2(0xeeed80, 0xc000480c00, 0xc0000895f0, 0xed85c0)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/executor/extensions.go:59 +0x42
github.com/99designs/gqlgen/graphql/executor.(*Executor).DispatchOperation.func1.1(0xeeed80, 0xc000480b70, 0xc000480b40)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/executor/executor.go:104 +0x131
github.com/99designs/gqlgen/graphql/handler/transport.POST.Do(0xeede90, 0xc0002880e0, 0xc00017aa00, 0xeed860, 0xc0001b02d0)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/handler/transport/http_post.go:53 +0x3a8
github.com/99designs/gqlgen/graphql/handler.(*Server).ServeHTTP(0xc0001a2bc0, 0xeede90, 0xc0002880e0, 0xc00017aa00)
        C:/Users/runneradmin/go/pkg/mod/github.com/99designs/gqlgen@v0.13.0/graphql/handler/server.go:115 +0x21b
github.com/gorilla/mux.(*Router).ServeHTTP(0xc0001d1b00, 0xeede90, 0xc0002880e0, 0xc00017a600)
        C:/Users/runneradmin/go/pkg/mod/github.com/gorilla/mux@v1.8.0/mux.go:210 +0xe5
github.com/rs/cors.(*Cors).Handler.func1(0xeede90, 0xc0002880e0, 0xc00017a600)
        C:/Users/runneradmin/go/pkg/mod/github.com/rs/cors@v1.7.0/cors.go:219 +0x1c6
net/http.HandlerFunc.ServeHTTP(0xc0001a2de0, 0xeede90, 0xc0002880e0, 0xc00017a600)
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/net/http/server.go:2069 +0x4b
net/http.serverHandler.ServeHTTP(0xc000210000, 0xeede90, 0xc0002880e0, 0xc00017a600)
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/net/http/server.go:2887 +0xaa
net/http.(*conn).serve(0xc000200b40, 0xeeed80, 0xc00002c080)
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/net/http/server.go:1952 +0x8cd
created by net/http.(*Server).Serve
        C:/hostedtoolcache/windows/go/1.16.3/x64/src/net/http/server.go:3013 +0x3b8

[neel1996]

@Nageswari-droid Fix is ready for #155. Approve the build to pick up the changes.