Compilation error on Qt5Core, Qt5Widgets, Qt5Quick

[CaptainQuirk]

Hi there,

I guess this is more or less the same than #18. Thought I create a new issue since I'm on Ubuntu 16.04.
When trying to install with go get github.com/cortex/gopass, I get

# pkg-config --cflags Qt5Core Qt5Widgets Qt5Quick
Package Qt5Core was not found in the pkg-config search path.
Perhaps you should add the directory containing `Qt5Core.pc'
to the PKG_CONFIG_PATH environment variable
No package 'Qt5Core' found
Package Qt5Widgets was not found in the pkg-config search path.
Perhaps you should add the directory containing `Qt5Widgets.pc'
to the PKG_CONFIG_PATH environment variable
No package 'Qt5Widgets' found
Package Qt5Quick was not found in the pkg-config search path.
Perhaps you should add the directory containing `Qt5Quick.pc'
to the PKG_CONFIG_PATH environment variable
No package 'Qt5Quick' found
exit status 1
# golang.org/x/crypto/openpgp/packet
.go/src/golang.org/x/crypto/openpgp/packet/private_key.go:69: undefined: crypto.Signer
.go/src/golang.org/x/crypto/openpgp/packet/private_key.go:71: use of .(type) outside type switch
.go/src/golang.org/x/crypto/openpgp/packet/signature.go:521: undefined: crypto.Signer
.go/src/golang.org/x/crypto/openpgp/packet/signature.go:545: undefined: crypto.Signer
# github.com/proglottis/gpgme
.go/src/github.com/proglottis/gpgme/data.go:4:20: fatal error: gpgme.h: No such file or directory
 // #include <gpgme.h>
                    ^
compilation terminated.

I use pass mostly from the command line, but I would like to make a demo at work. I'm not sure it'll be that convincing if there ain't any GUI available !

Thanks for your work !

[lcmaqueda]

@CaptainQuirk, Have you installed the requirements for qml-go? You can find detailed instructions for Ubuntu here