iOS-git忽略build和xcuserdata

1、生成或copy一个.gitignore
2、删除已提交过的build目录和xcuserdata文件，add新增的.gitignore，并提交push即可

# Object files
*.o
*.ko
*.obj
*.elf

# Precompiled Headers
*.gch
#*.pch

# Libraries
*.lib
#*.a
*.la
*.lo

# Shared objects (inc. Windows DLLs)
*.dll
*.so
*.so.*
*.dylib

# Executables
*.exe
*.out
*.app
*.i*86
*.x86_64
*.hex

# Debug files
*.dSYM/
*.su


.DS_Store
.Trashes
Icon?
._*
.Spotlight-V100
.Trashes
*.pbxuser
*.mode1v3
*.mode2v3
*.perspectivev3
*.xccheckout
!default.pbxuser
!default.mode1v3
!default.mode2v3
!default.perspectivev3
xcuserdata
build