Fernet

Fernet is used at run time in 5 crates.

Number of dependers	Fernet version	Downloads/month
3	0.2.1	4.7K
1	0.2.0	130
1	0.1.4	1.3K

Depender			Fernet version
		ayb		^0.2.1
		wdcrypt		^0.2.1
		solwalrs		=0.2.0
		safepass		^0.1
		encryptable		^0.2.1